A senior White House official says he expects Ukrainian President Volodymyr Zelenskyy to sign a deal that would give the US access to his country's natural resources. The administration of President Donald Trump has been pressuring Zelenskyy to accept the agreement.

During a political conference in Maryland on Friday, US National Security advisor Mike Waltz said that only Trump can bring about an end to the war.

Waltz said: "Here's the bottom line: President Zelenskyy is going to sign that deal, and you will see that in the very short term. And that is good for Ukraine."

He also suggested that the minerals deal was first proposed by Zelenskyy last year as part of his "victory plan."

Trump used a White House event on Friday to once again urge Ukrainian leaders. He said: "They don't have any cards, but they play it tough. But we're not, we're not going to let this continue."

The agreement calls for Ukraine to give the US access to critical minerals as compensation for defense aid. However, the two sides have been unable to reach a deal.

Trump this week denounced Zelenskyy as a "dictator" and warned him of the need to move quickly to secure peace with Russia. He lashed out in an interview on Fox News Radio that he does not think it is important for Zelenskyy to attend peace talks.

Zelenskyy posted Friday on social media about the importance of US support, adding that "strong and lasting peace can only be achieved through unity."