The United States national security advisor, Mike Waltz, has warned Ukraine’s leader to stop hurling insults at Donald Trump, as pressure built Friday on Volodymyr Zelensky to sign away mineral rights in exchange for Washington’s help to defend against Russia.

Waltz stressed that President Trump is very frustrated with President Zelensky’s attitude, noting that he hasn’t been willing to take the offer made by Ukraine.

The United States is a vital financial and military supporter of Ukraine, but Trump has rattled Kyiv and its European backers by opening talks with Moscow, which they fear could end the war on terms that reward Russian President Vladimir Putin.

This tussle seems to have turned personal with President Trump falsely claiming Zelensky is hugely unpopular among his own people and the Ukrainian leader saying Trump lives in a Russian disinformation space.

Tensions between Trump and Zelensky over the proposed mineral deal which Ukraine has rejected, as Washington’s outreach to Moscow have exploded this week in a series of barbs traded at press conferences and on social media.

President Zelensky has warned that Trump has succumbed to Russian disinformation, while the US leader has accused his counterpart of starting the war and branded him a dictator without elections.

Amid the war of words, Zelensky said he had held a productive meeting with US envoy Keith Kellogg in Ukraine.

9News Nigeria reports that some of his words were; “We had a detailed conversation about the battlefield situation, how to return our prisoners of war, and effective security guarantees,” Zelensky said on social media after the meeting.

“Strong Ukraine-U.S. relations benefit the entire world,” he added.