Reykjavik, Iceland - NATO Secretary General Mark Rutte on Thursday praised President Donald Trump's efforts to end Russia's war in Ukraine, the deadliest conflict in Europe since World War II.

"There is tremendous renewed energy around the peace process, and for that I want to commend US President Trump," Rutte told reporters during a visit to Iceland, where he met with Prime Minister Kristrun Frostadottir.

A US-proposed ceasefire has breathed new life into negotiations, with officials from Russia, Ukraine, Washington, and Europe ironing out conditions in talks spanning from Geneva to Abu Dhabi.

Washington has not published its latest plan, but Trump has called it a "fine-tuned" update of a previous 28-point proposal that was firmly rejected by Kyiv and its European allies for being what they said was a Kremlin wish-list.

Donald Trump Democrats accuse Trump of escalating campaign of "intimidation" as FBI steps in

The Kremlin has said it views some of the updated plan "positively", but said other points required further discussion.

Ukrainian President Volodymyr Zelensky has meanwhile said the "principles" of the plan could lead to "deeper agreements".

US special envoy Steve Witkoff is due to visit Moscow next week to meet with Russian President Vladimir Putin.