BBC | Ukraine is preparing to present a revised peace plan to the White House, as it seeks to avoid making territorial concessions to Russia.
Kyiv is set to propose alternatives to the US after President Volodymyr Zelensky again ruled out surrendering land, saying he had "no right" to do so under Ukrainian or international law.
He made the comments as he met European and Nato leaders on Monday, part of a collective push to deter the US from backing a peace deal which includes major concessions for Ukraine, and which allies fear would leave it vulnerable to a future invasion.
Meanwhile, the city of Sumy in north-western Ukraine was left without power overnight after a Russian drone attack.
The region's governor said more than a dozen drones had hit power infrastructure, the latest in Russia's nightly attacks. No deaths were reported.
Zelensky's ongoing diplomatic tour of Europe comes after days of intensive talks between US and Ukrainian negotiators over the weekend, that failed to produce a deal Kyiv could agree to.
Zelensky was due to be briefed on that private summit on Monday by his chief aide Rustem Umerov, who wrote on Telegram that he would feed back details of direct talks between the US and Russian President Vladimir Putin.