Volodymyr Zelenskyy has said Ukraine received no advance alert from the United States before a Russian missile assault on Sunday night, prompting renewed fears in Kyiv that Washington may be limiting intelligence support to pressure Ukraine into making concessions to Moscow.

Yuri Ihnat, a spokesperson for Ukraine’s air force, said in a television interview on Monday that no warning was received before Russian missiles struck energy infrastructure in Kyiv at around 11pm. A Ukrainian government source had earlier said that the capital had not been alerted by the US before the attack.

Ihnat said Ukraine was later warned ahead of another wave of strikes at about 3am.

“Once again, Russia carried out a ballistic missile attack in several waves overnight, and once again there was no warning from our partners,” Zelenskyy said in a social media message on Monday morning.

“When deliveries of missiles for Ukrainian air defence are obstructed, while Russia benefits from sanctions exemptions or delays, that is unfortunately a refusal by our partners to face reality,” he added.

Zelenskyy has been confronting a series of recent US decisions that Kyiv believes have helped Vladimir Putin.

On Friday, Donald Trump suspended a broad sanctions package targeting Russia, telling Congress that delaying the legislation, named after the late senator Lindsey Graham and approved by both houses, was necessary for US national interests. Ukraine has also raised concerns over slower US deliveries of PAC-3 air defence missiles.

The US president wrote on social media on Sunday: “My position on Russia is very straightforward. I am trying to negotiate peace in the war between Russia and Ukraine, and I do not want to do anything that would recklessly push Russia away from the negotiating table.

“Zelenskyy does not care, and frankly, despite all the money Europe is supposedly giving him, he does not want the war to end and perhaps never did.”

Trump also told reporters on Monday that he was open to holding a meeting involving Russia and China. “We would discuss nuclear weapons and denuclearisation,” he said. “If President Xi wants such a meeting, I would take part.”

For years, the US has alerted Ukraine before Russian ballistic missile launches, allowing several minutes for air raid sirens to be activated and civilians to reach shelters. Ukraine has said, however, that it received no such warning on at least three occasions during the past week, amid a public dispute between Zelenskyy and Trump.

Speaking early on Monday while visiting Samarkand in Uzbekistan, the US secretary of state, Marco Rubio, said: “If it happened last night, I do not know the details. I know that a few nights ago there was a software issue involving their early warning system.”

US officials had not previously referred to any software malfunction affecting the warning network. In at least one instance, Ukrainian officials were reportedly told that poor weather in southern Russia had made it difficult to monitor preparations for a missile launch. Rubio said US European Command was reviewing the attacks.

The US has sought to preserve uncertainty over whether support systems and services used by Ukraine have been deliberately restricted or have failed for other reasons. The Trump administration has denied limiting access in Ukraine to Starlink, Elon Musk’s satellite internet network, which is used by Ukrainian forces for both drone operations and air defence activity.

Ukraine has also said that US weapons supplied through the PURL arrangement, under which European countries buy American arms for transfer to Ukraine, have arrived more slowly than expected. Reports have suggested that Washington warned Kyiv that key military deliveries could be reduced unless it stopped attacks on Russian oil refineries.

On Sunday, Ukraine sent more than 1,000 drones into Russia in one of the largest aerial operations of the war, causing fires at an oil export facility and a storage depot in St Petersburg.

Zelenskyy said the Russian strike on Sunday evening damaged 28 substations and other vital energy sites, cutting electricity, heating and water supplies for more than 500,000 people. Russia has repeatedly targeted civilian life in Ukraine through attacks on railways, shopping areas, fuel facilities and supermarkets, among other locations.

Russia launched 16 ballistic missiles at Kyiv and the surrounding area, Zelenskyy said. Authorities in the capital reported that a 21-year-old woman had been killed.

Later drone attacks on a public park in the north-eastern Kharkiv region killed six people, including small children. The regional governor, Oleg Synegubov, said three of those killed in Nova Vodolaha were children, including one who had been in a pushchair. Fourteen people were injured, seven of them children. Police released images showing wrecked playground equipment.

Synegubov described the strike as “another terrorist act by the Russian Federation”, saying the attack had hit a leisure park in daylight despite the absence of any military facility in the area.

Pope Leo XIV spoke with Zelenskyy by telephone on Monday about the embattled city of Oleshky in Ukraine’s Kherson region, according to the Vatican. The pope told the Ukrainian president that he had asked Putin for a humanitarian ceasefire during a conversation with the Russian leader on Friday.

People living in Oleshky are facing an increasingly severe humanitarian emergency, including shortages of food and medicine, while caught between Russian and Ukrainian forces. The Vatican said Leo had voiced serious concern over conditions there and called for a truce that could allow aid to enter and civilians to be evacuated.

The conversation with Zelenskyy took place two days after Leo, 71, left a hospital in Rome following surgery for lung cancer last Tuesday.

The Kremlin said on Friday that it had explained to Leo what it described as “the Kyiv regime’s responsibility for the difficult humanitarian situation”.