United States National Security Adviser Mike Waltz on Monday welcomed European leaders' effort to try to end the war between Russia and Ukraine.

"They're certainly showing a will, and they - both [United Kingdom's Prime Minister Keir] Starmer and [French President Emmanuel] Macron - showed that will last week, before Friday. We also had the NATO Secretary General [Mark Rutte] on the phone with the president, before [Ukrainian] President [Volodymyr] Zelensky came in. So we welcome Europe stepping up for Europe, but they also have to invest in the capabilities to do so," Waltz told reporters. He added that even before Zelensky visited the White House on Friday, it was clear that Europe was planning to boost its contribution to Ukraine's security.

The day before, Starmer revealed that the UK, France, and Ukraine are committed to setting up a plan to end the conflict with Russia.