Ukrainian President Volodymyr Zelensky needs to return to the negotiating table and strike a deal on US access to Ukraine’s critical minerals, White House national security adviser Mike Waltz has said.On Wednesday, Zelensky rejected US demands for a share of its rare earth minerals – a “deal” Trump said would reflect the amount of aid the US had provided to Ukraine during its war with Russia.The comments, made at a White House briefing on Thursday, overshadowed a meeting in Kyiv between Zelensky and Keith Kellogg, the US chief envoy to Ukraine.Waltz said the White House was “frustrated” with Zelensky after he levelled “unacceptable” insults at US President Donald Trump earlier this week.Ukraine holds huge deposits of critical elements and minerals, including lithium and titanium, as well as sizeable coal, gas, oil and uranium deposits – a supply worth billions of dollars.Earlier on Thursday, Waltz suggested US access to rare minerals in Ukraine could be exchanged in return for aid – or even as compensation for the support the US has already provided.”We presented the Ukrainians really an incredible, and a historic opportunity,” the adviser said, adding that it would be “sustainable” and “the best” security guarantee Ukraine could hope for.But Zelensky had refused the offer, saying: “I can’t sell our state.”Waltz’s comments in the White House news briefing came shortly after the conclusion of Zelensky’s meeting with Kellogg in Kyiv, after which the Ukrainian leader announced he was ready to make an “investment and security agreement” with the US to end the war in Ukraine.The meeting was hailed as “productive” by Zelensky – but it more closely resembled an awkward political date.As the senior members of Donald Trump’s team continued to engage directly with Moscow, the retired general had said he was in Kyiv to “listen”.But it soon became apparent he wo …