Ukrainian soldiers broke through Russian lines south of the city on Wednesday and have since exploited this breach and assaulted Russian forces elsewhere near Bakhmut, the Ukrainian military said, threatening their flanks to the north and south.

The Russian ministry of defense acknowledged on Friday that its forces had been forced to fall back along one line to the northwest of the city and had regrouped near a reservoir, but the ministry continued to deny that Ukrainian forces had broken through Russian lines.

Tensions among Russia’s disparate forces are spilling into the open as the Ukrainian military exerts more pressure on them around Bakhmut, increasing concerns among some prominent war supporters ahead of Kyiv’s announced counteroffensive.

The chief of the Wagner mercenary group, Yevgeny V. Prigozhin, who has long been an aggressive critic of Russia’s military leaders, this week issued a series of expletive-laden audio and video messages, moving into new territory with comments that some observers interpreted as his first direct criticism of President Vladimir V. Putin of Russia.

Cracks appeared elsewhere, too, as the Chechen strongman Ramzan Kadyrov, whose paramilitary forces have fought alongside Wagner in Ukraine, criticized Mr. Prigozhin, his longtime ally, in a video broadside.

Recriminations plague Russian forces as Ukraine steps up pressure

Tensions among Russia’s disparate forces are spilling into the open as the Ukrainian military exerts more pressure on them around Bakhmut, increasing concerns among some prominent war supporters ahead of Kyiv’s announced counteroffensive.

The chief of the Wagner mercenary group, Yevgeny V. Prigozhin, who has long been an aggressive critic of Russia’s military leaders, this week issued a series of expletive-laden audio and video messages, moving into new territory with comments that some observers interpreted as his first direct criticism of President Vladimir V. Putin of Russia.

Cracks appeared elsewhere, too, as the Chechen strongman Ramzan Kadyrov, whose paramilitary forces have fought alongside Wagner in Ukraine, criticized Mr. Prigozhin, his longtime ally, in a video broadside.

China will send an envoy to Russia and Ukraine in a quest for peace talks

A Chinese government envoy will visit Ukraine and Russia next week in an attempt to help negotiate an end to the war, a Chinese government spokesman said on Friday.

China had announced its intention to send the official, Li Hui — the government’s special representative for Eurasian affairs — after a phone call last month between its top leader, Xi Jinping, and Ukraine’s president, Volodymyr Zelensky. Beijing had said that Mr. Li would “conduct in-depth communication with all parties” to try to reach a “political settlement.”

Beijing has been trying to position itself as a potential peace broker in the war, especially as Mr. Xi casts himself as a global statesman and China as an alternative to the United States for global leadership. In February, China issued what it described as a 12-point peace plan for Ukraine, though Western officials criticized it as lacking substance.

Turkish opposition leader accuses Kremlin of election meddling, straining a strategic alliance

A Turkish opposition leader on Friday doubled down on accusations that Russia is interfering in the country’s election, adding uncertainty over the future of one the region’s most important strategic partnerships.

The opposition leader, Kemal Kilicdaroglu, who holds a slight edge in most polls over the long-serving incumbent Recep Tayyip Erdogan in the race for president, told Reuters on Friday that he has evidence of Russia manufacturing “deep fake” videos to influence Sunday’s vote. He did not provide details.

Mr. Kilicdaroglu’s claim came after he accused Moscow in a Twitter post on Thursday of being “behind the montages, conspiracies, deep fakes and tapes that were exposed in this country yesterday.”

Top E.U. diplomat vows to stand with Ukraine for the long haul

The European Union’s top diplomat again voiced the bloc’s strong support for Ukraine in its struggle against Russia on Friday, vowing that Europe would not tire of supporting Kyiv on or off the battlefield, as the Kremlin might hope.

The bloc must continue to give Ukraine immediate, practical support on the battlefield in the form of arms, while preparing long-term commitments of humanitarian and economic aid, said the diplomat, Josep Borrell Fontelles, adding that it would continue to work toward the country’s accession to the European Union — “our ultimate commitment.” Speaking at a joint news conference with the Swedish foreign minister following an informal meeting of E.U. foreign ministers in Stockholm, Mr. Borrell stressed Russia’s responsibility for the war, saying Ukraine had to keep fighting if it wanted to continue to exist as a nation. He reiterated his support for President Volodymyr Zelensky’s proposed peace plan, which the Kremlin has fully rejected because it would require surrendering all captured Ukrainian territory.

“We want peace, but we want a capitulation. We don’t want Ukraine to become the second Belarus,” Mr. Borrell said, referring to the former Soviet nation that has long been held under Moscow’s sphere of influence.

Russian-ordered evacuations near Ukraine’s Zaporizhzhia nuclear plant alarm officials

KYIV, Ukraine — The situation at the Zaporizhzhia Nuclear Power Plant is growing more precarious as the Russian occupation authorities shutter essential services in the nearest town, evacuate residents and exert new stresses on beleaguered employees, Ukrainian officials and the United Nations watchdog agency warned this week.

While all six reactors at the Russian-occupied facility are shut down, workers still need to keep critical safety equipment operating in order to prevent a possibly catastrophic release of radiation. Pressure on those employees deepened this week as the Russian occupation authorities began closing banks, shops and key services in Enerhodar, the town where the remaining plant workers and their families live, and relocating residents before a looming Ukrainian counteroffensive.

Rafael Mariano Grossi — the director general of the International Atomic Energy Agency, the U.N. agency that has stationed monitors at the plant — said on French television on Wednesday that the evacuation order was alarming because it was “a harbinger of military activities or actions” in an area that is “already the subject of much concern.”

Turkey says talks about extending the grain deal are ‘positive’

Ukraine and Russia are getting closer to reaching an agreement to extend the imperiled Black Sea grain deal, Turkey’s defense ministry said on Friday, after two days of talks failed to conclusively salvage it.

Moscow has threatened to pull out of the deal when it expires on May 18. Representatives from Russia, Ukraine, Turkey and the United Nations met this week for talks aimed at securing an extension to the agreement, which has allowed Ukraine to export millions of tons of grain from its ports on the Black Sea despite the war.

Turkey’s foreign minister, Mevlut Cavusoglu, said this week that he thought the deal could be extended for “at least two months.” But no concrete announcement was made after talks concluded on Thursday, and Turkey’s defense ministry said that talks would “continue in the coming days.”

Kherson was a symbol of hope when it was liberated. Now ‘death is everywhere.’

KHERSON, Ukraine — The road to Kherson is long, straight and empty. Vacant fields rise from either side.

Entering town from the west, you pass the ATB supermarket, one of the mainstays of the city’s shopping. It was blown up a few weeks ago, in the middle of the day, with shoppers inside.

After that lie more crushed buildings, disassembled by Russian artillery shells.

Zelensky’s comments about needing more time for a successful counteroffensive set off a debate on any hidden agenda

KYIV, Ukraine — When President Volodymyr Zelensky of Ukraine said in a BBC interview that he was delaying the counteroffensive to retake Ukrainian land from Russia, it set off immediate debate about what he really meant. His reasoning was that although his troops were ready, starting without what he considers adequate weaponry would mean too many Ukrainian lives lost.

For Ukrainian analysts, the answer to what he was thinking was simple.

“It’s true,” said Taras Chmut, a former military officer who heads Come Back Alive, a charitable foundation that provides military supplies for the Ukrainian Army. “The amount we gathered in recent months is still not enough for a successful counteroffensive.”

Japan says NATO is in talks about opening an office in the country as the two seek stronger ties

NATO is considering opening a liaison office in Japan, the country’s officials said this week, a move that international security experts say could deepen the alliance’s engagement in the region as it grows increasingly concerned about China’s support of Russia.

Discussions about the office, which would be NATO’s first in Asia, are underway but no decisions have been made, the Japanese foreign minister, Yoshimasa Hayashi, said at a Parliament session on Wednesday.

“Something happening in East Europe is not only confined to the issue in East Europe, and that affects directly the situation here in the Pacific,” he later told CNN, saying that this was why a cooperation with NATO was “increasingly important.”

The United States is wiring Ukraine with radiation sensors to detect nuclear blasts

The United States is wiring Ukraine with sensors that can detect‌‌ bursts of radiation from a nuclear weapon or a dirty bomb and can confirm the identity of the attacker.

In part, the goal is to make sure that if Russia detonates a radioactive weapon on Ukrainian soil, its atomic signature and Moscow’s culpability could be verified.

Ever since Russia invaded Ukraine, experts have worried about whether President Vladimir V. Putin of Russia would use nuclear arms in combat for the first time since the American bombings of Hiroshima and Nagasaki in 1945. The preparations, mentioned in March in a House hearing and detailed recently by the National Nuclear Security Administration, a federal agency that is part of the Energy Department, seem to constitute the hardest evidence to date that Washington is taking concrete steps to prepare for the worst possible outcomes of the invasion of Ukraine, Europe’s second largest nation.