US Vice-President JD Vance has said Russia made "significant concessions" to Donald Trump and rejected suggestions Moscow is slow-walking a potential peace deal in Ukraine.
In a pre-recorded interview that aired on Sunday, Mr Vance said Mr Trump, who met his Russian presidential counterpart Vladimir Putin this month at an Alaska summit, has been engaged in "very aggressive, very energetic diplomacy" with both Moscow and Kyiv in a bid to find a compromise solution that would stop the killing.
"I think the Russians have made significant concessions to President Trump for the first time in three and a half years of this conflict," Mr Vance told NBC's Meet the Press.
"They've actually been willing to be flexible on some of their core demands."
That included Russia conceding it could not install a Kremlin-friendly government in Ukraine, and that Ukraine would remain territorially sovereign after the war.
"And importantly, they've acknowledged that there is going to be some security guarantee to the territorial integrity of Ukraine," he said.
But the vice-president would not be drawn on whether Ukraine's borders could change as a result of a peace settlement.
Mr Vance's comments came after Russian Foreign Minister Sergei Lavrov accused Western countries of seeking "a pretext to block negotiations".
Mr Lavrov in particular slammed Ukrainian President Volodymyr Zelenskyy for "demanding an immediate meeting at all costs".
On Friday, Mr Trump renewed a threat to impose sanctions on Russia if there was no progress toward a peaceful settlement in Ukraine in two weeks, showing frustration at Moscow a week after his meeting with Mr Putin in Alaska.
Ukrainian forces on Sunday launched drone strikes on Russia, triggering a fire at a nuclear power plant.
Ukrainians celebrate 34th year of independence
Mr Vance and Mr Lavrov's comments came as Ukrainians marked the country's independence day for the fourth time since the war began.
In recent years, Mr Putin has sought to portray Ukraine's independence as an accidental outcome of the Soviet Union's dissolution and described Ukrainians and Russians as "one people".
But as people gathered in Kyiv on Sunday, it was clear many Ukrainians disagreed with that argument.
Speaking to the ABC, Margaret said independence day meant celebrating Ukraine's differences from other countries.
"After [the invasion] we understood we are a nation … and we are united," she said.
With Ukraine's future being debated by world leaders, Daria said it was important to continue celebrating the country's independence.
But the Kyiv resident also said the rising death toll from Russia's invasion was "heartbreaking".
Europeans show solidarity with Ukraine
While large gatherings were banned in Kyiv for security reasons, hundreds took to the streets in rallies for Ukraine across Europe.
In London, the path across from Downing Street became a sea of yellow and blue as hundreds of people gathered to show their support.
Natalia Hendry has lived in the UK for 10 years but felt it was important to show up on behalf of friends and family who are still in Ukraine.
"The most important thing is supporting them and for them to know we remember them," Ms Hendry said.
"For them to know we not forget, that we are still trying — not to fight, but to support."
Across the crowd, Natalia Edwards paid tribute to the men and women on the front line, proudly flying a Ukrainian flag signed by serving soldiers.
One of the signatures belongs to the brother of her friend Basil, who also attended the rally. He's been fighting Russia since its takeover of Crimea in 2014.
Hundreds of people gathered at a similar rally in Paris, where organisers led the march calling for Ukraine to maintain its independence, in the event of a peace deal.
"We really must help because we, as a European family, must be united to defeat this aggression from Russia," said attendee Karina Yakymenko, who is originally from Kyiv.
Those calls were echoed in St Peter's Square, where Pope Leo used his weekly address to renew his appeal for peace in Ukraine.
"In asking you not to forget these brothers and sisters of ours. I invite you to pray for them," he said.
"I express my hope that the efforts of these countries' leaders will succeed in restoring security and peace."
ABC/wires