As Ukrainians emerge from war ruins, U.S. officials warn that Russia plans to start annexing territory

As battered, sun-starved Ukrainians trickled out from the ruins of the port city of Mariupol, Russian forces Monday pressed new bombing runs in the east and south of the country and U.S. officials warned Moscow will attempt to annex larger chunks of territory it occupies.

How many Ukrainians were finally allowed to escape a city devastated by steady Russian artillery was not immediately clear. Ukrainian officials said that in a number of evacuations, Russian forces have re-routed those fleeing to Russian-held territory against their will.

Families that did reach the Ukrainian-held city of Zaporizhzhia under auspices of the United Nations told of harrowing trips filled with dread — after two months of struggling to survive in the darkened tunnels underneath Mariupol's steel plant. Hundreds of wounded Ukrainian soldiers and more civilians remain holed up there, the last Ukrainian redoubt as most of the city has fallen to Russia.

A senior Pentagon official, meanwhile, said Russia's offensive to take the Donbas region in the east continues to be "uneven and incremental and even anemic in many places." He said Russian forces were zeroing in on the northern city of Kharkhiv, which sits on the northwestern edge of the Donbas.

U.S. officials believe Russia plans to annex the Donetsk and Luhansk breakaway regions in the Donbas region, which President Vladimir Putin has declared to be independent republics, and then do the same with the Kherson region in the south near the port city of Odesa. It would follow the steps taken by Putin after he occupied Ukraine's Crimean peninsula in 2014.

"We have to act urgently," Michael Carpenter, the U.S. ambassador to the Organization for Security and Cooperation in Europe, told reporters in Washington. He said the illegal annexations could happen as early as mid-May through a series of staged "sham referenda" made to look as if residents were voting for the measure, as Russian authorities would impose puppet local officials, Russian-language school curriculum and even the use of rubles.

Monday's developments came as House Speaker Nancy Pelosi wrapped up an unannounced weekend visit to Kyiv and a meeting with the president of Poland, where she thanked him and his country for taking in the lion's share of the more than 5.5 million Ukrainians who have fled their country since the war there began.

Speaking alongside a group of fellow congressional Democrats, Pelosi issued a statement expressing "America's deep gratitude to the Polish government and Polish people."Polish President Andrzej Duda, in brief public remarks, called the war a "crucial" time for his country.

Pelosi departed the region later Monday. Her swing through Ukraine and Poland followed a similar tour last week by the U.S. secretaries of State and Defense.

The White House said Monday that First Lady Jill Biden would travel to Slovakia and Romania over the coming weekend to meet U.S. military service members as well as government and humanitarian workers dealing with an influx of refugees.

In his nightly video address, Ukrainian President Volodymyr Zelensky said he expected about 100 Mariupol civilians who were evacuated Sunday to arrive Monday in Zaporizhzhia, with more to follow.

He described evacuation corridors as one of the few areas of progress in off-and-on talks between Russia and Ukraine. He said about 350,000 people had been given safe passage from battle zones over the last months.

At the same time, there was a report of new attacks on Mariupol, a once-thriving cosmopolitan city that dwindling food supplies and reported mass graves have turned into a symbol of the war's brutality.

A mayoral aide, Petro Andryushchenko, said Monday that Mariupol's Azovstal steel plant was hit with shelling Sunday even as evacuations overseen by the U.N. and the International Red Cross were taking place.

"As soon as the buses left Azovstal with the evacuees, new shelling began immediately," Andryushchenko said in a Ukrainian TV interview.

The Mariupol City Council said in a statement Monday that, "despite all the difficulties, the evacuations of civilians from Mariupol to Zaporizhzhia must take place.”

Even local officials have struggled to obtain information on the situation at the steelworks. Some estimates have put the number of Ukrainians still trapped at 600. Others have said there are at least 2,000 people taking shelter in the complex, which is surrounded by Russian troops.

A commander in Ukraine's national guard, Denys Shlega, said Sunday in a televised interview that there were "several dozen small children" there as well as 500 injured soldiers and "numerous" bodies.

The worst fighting continued overnight in eastern Ukraine, where a 300-mile battlefront has become a center of Russia's attempt to capture the industrial Donbas region. Odesa, the jewel of Ukraine's Black Sea coast, was also hit by missiles Monday, with several dead reported.

In its morning operational update, the Ukrainian military said that Russia had deployed more antiaircraft missile systems in occupied areas of Luhansk, one of the two provinces that make up the Donbas, and that there was a continuing threat of missile strikes in the battle zone from Belarus, Ukraine's northern neighbor and an ally of Russia.

Zelensky said Russia had also hit residential neighborhoods along with food warehouses in other areas of the Donbas as well as in Kharkiv, Ukraine's second-biggest city, and that Putin was conducting a "a war of extermination."

Meanwhile, two Russian Raptor-class patrol boats were destroyed early Monday near Snake Island in the Black Sea, the Ukrainian military said. On the Telegram messaging app, it posted what appeared to be drone footage of one of the vessels taking a direct hit, but the video’s authenticity could not immediately be confirmed.

For its part, Russia said its warplanes struck 38 Ukrainian targets, including concentrations of troops and weapons, over the previous 24 hours. A spokesman for the Russian Defense Ministry said that an airstrike also destroyed an ammunition depot in the Zaporizhzhia region and that a Ukrainian MiG-29 fighter jet was downed near the eastern town of Slovyansk. The claims could not be independently verified.

The British Defense Ministry said a quarter of Russian troops dispatched to Ukraine are now "combat ineffective," meaning that they are unable to complete their mission because of casualties and equipment losses.

The ministry said 65% of Russia's combat forces have been assigned to Ukraine since the war began, with some of the greatest setbacks hitting the best-trained units. "It will probably take years for Russia to reconstitute these forces," it said.

Still, much of Ukraine has remained on alert, including the relatively peaceful western city of Lviv, a transit point for refugees fleeing west and a center for humanitarian aid.

Air-raid sirens regularly blast in the city, as in other regions of the nation. Over the weekend, a video went viral of actor Angelina Jolie — a special envoy of the U.N. High Commissioner for Refugees — meeting orphans in Lviv as sirens blared in the background.

In Odesa, fears have grown over increasing attacks as Moscow attempts to take Ukraine's Black Sea coast, in a move that would connect Russia, Russia-controlled Crimea and a pro-Russia separatist region in Moldova.

In a Telegram post Monday, regional government spokesman Serhiy Bratchuk said that a key bridge on the Dniester estuary had been hit for the third time. Over the weekend, Russia also said it had taken aim at an airport outside the city, leaving it nonfunctional.

In the Ukrainian capital, Kyiv, one sign of a return to limited normality was the decision by the U.S. — following several other nations — to send its diplomats back to the nation.

The U.S. Embassy, which moved its operations out of Kyiv before the start of the war, reestablished a mainly symbolic foothold in the country when its top diplomat traveled Monday from Poland to Lviv for meetings with Ukrainian officials, and said she would be visiting regularly.

The U.S. charge d’affaires, Kristina Kvien, told reporters that Washington hoped to again have a diplomatic presence in Kyiv by month’s end. Several Western countries have already reopened their embassies in the capital; Britain’s ambassador returned last week. Denmark also reopened its embassy Monday.

The United States has been without an ambassador to Ukraine since 2019, when then-President Trump removed veteran diplomat Marie Yovanovitch from her post in Kyiv.

She became a witness in his first impeachment for alleged abuse of power and obstruction of Congress, charges that stemmed from a phone call in which Trump urged Zelensky to dig up dirt on then-presidential candidate Joe Biden and Biden's son Hunter.

President Biden has picked Bridget Brink, the current envoy to Slovakia, to replace Yovanovitch. Kvien said Brink would take up her duties as soon as she is confirmed by the Senate.

King reported from Lviv, Kaleem from London and Wilkinson from Washington.

This story originally appeared in Los Angeles Times.