Rescuers work on the remains of a building damaged by shelling, as Russia’s invasion of Ukraine continues, in Kharkiv, Ukraine March 18, 2022. REUTERS/Oleksandr Lapshyn

Ukraine’s food supply system is falling apart under Russia’s invasion, with infrastructure destroyed and shops and warehouses growing empty, the United Nations said on Friday.

With Moscow trying to regain the initiative in a stalled campaign, Russia fired missiles at an airport near Lviv, a city where hundreds of thousands found refuge far from Ukraine’s battlefields.

US President Joe Biden was due to talk with Chinese president Xi Jinping, in an attempt to starve Russia’s war machine by isolating Moscow from the one big power that has yet to condemn its assault.

More than three weeks since President Vladimir Putin launched an invasion to subdue what he calls an artificial state undeserving of nationhood, Ukraine’s elected government is still standing and Russian forces have not captured a single big city.

Russian troops have taken heavy losses while blasting residential areas to rubble, sending more than 3 million refugees fleeing. Moscow denies it is targeting civilians in what it calls a “special operation” to disarm its neighbor.

“Russian forces have made minimal progress this week,” Britain’s defense ministry said in a daily military intelligence update. “Ukrainian forces around Kyiv and Mykolaiv continue to frustrate Russian attempts to encircle the cities.”

At least three blasts were heard near Lviv’s airport on Friday morning. The mayor, Andriy Sadovy, said several missiles had struck an aircraft maintenance facility, destroying buildings but causing no casualties.

The city, near the Polish border, is hundreds of miles from Russia’s advance and has been one of the main destinations for Ukrainians forced to flee battle zones.

Jakob Kern, emergency coordinator for the crisis at the UN World Food Program, said Ukraine’s “food supply chain is falling apart. Movements of goods have slowed down due to insecurity and the reluctance of drivers”.

WFP, which feeds people in global crisis zones, also buys nearly half of its wheat from Ukraine. Kern said the war has already driven global food prices to all time highs, and could cause “collateral hunger” in poor countries worldwide.

INTENSE SHELLING

Russia has been intensively shelling eastern Ukrainian cities, especially Chernihiv, Sumy, Kharkiv and Mariupol.

Among those killed in Chernihiv was Jimmy Hill, 68, an American working in Ukraine as a university lecturer, trapped in the besieged city looking after his Ukrainian partner who was hospitalized with illness. He was gunned down by Russian snipers while waiting in a bread line, and his body was found in the street, his family said.

Russia denied blame for the deaths.

In his last Facebook post, he wrote that his partner was in intensive care. “Intense bombing! still alive. Limited food. Room very cold.”

Kyiv has so far been spared a major assault, with long columns of troops bearing down from the northwest and east halted at the gates in heavy fighting. But residents in the capital have endured nightly deadly missile attacks.

Debris from a missile blew a large crater in the ground in the middle of a residential block where a school was also located in northern Kyiv on Friday, shattering hundreds of windows and leaving debris scattered around the complex.

At least one person was killed, emergency services said. Kyiv mayor said 19 people were injured including four children.

“This is a war crime by Putin,” said Lyudmila Nikolaenko, visiting her son, who lived in one of the apartments hit. “They say they aren’t hitting regular people, they say we are firing at ourselves.”

In Mariupol, Ukraine said it had so far rescued 130 people from the basement of a theatre used as a bomb shelter when it was flattened by Russian strikes two days ago. Kyiv said it feared as many as 1,000 could still be trapped inside. It has given no information yet about dead or wounded. Russia denies hitting the theatre.

BIDEN PUTTING PRESSURE ON BEIJING

Peace talks have stepped up this week, with Kyiv, which is demanding a Russian ceasefire and withdrawal, saying Moscow has become more serious as quick victory slips out of its reach.

Both sides have described progress towards a political formula that would keep Ukraine out of the NATO alliance but protected with some other form of guarantee. Both, however, accused each other on Friday of dragging the talks.

With financial sanctions and diplomatic ostracism cutting Russia off from advanced economies, China is Russia’s last big economic lifeline.

Putin and Xi signed a “no limits” friendship pact three weeks before the invasion, in an ostentatious event held on the morning of last month’s Winter Olympics opening ceremony. The document repeated some of Russia’s grievances over Ukraine.

China has so far been treading a careful line, abstaining in votes over UN resolutions condemning Russia while declining to refer to the assault as an invasion criticizing the West.

But Washington, which this week announced $800 million in new military aid to Kyiv, now says Moscow wants more from Beijing than just diplomatic cover, and has asked for money and weapons to keep the war going, which Moscow and Beijing deny.

The United States is concerned China is “considering directly assisting Russia with military equipment to use in Ukraine,” Secretary of State Antony Blinken said.

Biden, who described Putin as a “murderous dictator,” will make clear to Xi that China “will bear responsibility for any actions it takes to support Russia’s aggression”, Blinken told reporters. The two leaders were due to speak at 1300 GMT.

“Beijing will do everything in its power to avoid having to openly take sides, but its formerly relatively cost-free relationship with Russia has become complicated and is now exposing China to growing geopolitical, economic and reputational risks,” said Helena Legarda, Lead Analyst at the Mercator Institute for China Studies.

Hours before the phone call, China sailed an aircraft carrier through the sensitive Taiwan Strait — shadowed by a US destroyer — a person with direct knowledge of the matter said.