Washington, Feb 21 : US National Security Adviser Mike Waltz urged Ukrainian President Volodymyr Zelensky to "tone down" its stance and return negotiations over a minerals deal with the US.

"They need to tone it down and take a hard look and sign that deal," Waltz told Fox News.

The proposed agreement, which reportedly demands a 50-per cent share of Ukrainian natural resources, was initially presented by US Treasury Secretary Scott Bessent at the Munich Security Conference, Xinhua news agency reported.

"You really need to sign this," Bessent reportedly told Zelensky during their meeting.

However, Kyiv has so far rejected the US proposal. "I can't sell our state," Zelensky said on Wednesday.

"In total, the United States separately gave us about $67 billion in weapons, and we received $31.5 billion in budget support," he said, adding: "But one cannot count up to $500 billion and say, 'give us back $500 billion in minerals,' that's not a serious discussion."

Despite this, the Ukrainian leader said Ukraine is grateful for the support and is open to discussing a deal that includes US security guarantees for his country.

Following a meeting in Kyiv with Keith Kellogg, the US special envoy for Ukraine and Russia, Zelensky described their talks as "productive" in a post on the social platform X on Thursday.

"Ukraine is ready for a strong, effective investment and security agreement with the President of the US. We have proposed the fastest and most constructive way to achieve results," he wrote.

/IANS