The US national security adviser warned Ukraine's leader to stop hurling "insults" at Donald Trump, as pressure built Friday on Volodymyr Zelensky to sign away precious mineral rights in exchange for Washington's help defending against Russia.
Tensions between Trump and Zelensky over the proposed mineral deal - which Kyiv has rejected - and Washington's outreach to Moscow have exploded this week in a series of barbs traded at press conferences and on social media.
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".
"Some of the rhetoric coming out of Kyiv, frankly, and insults to President Trump were unacceptable," US national security advisor Mike Waltz told a Thursday briefing at the White House.
"President Trump is obviously very frustrated right now with President Zelensky, the fact that he hasn't come to the table, that he hasn't been willing to take this opportunity that we have offered," he said.
The US is a vital financial and military supporter of Ukraine, but Trump has rattled Kyiv and its European backers by opening talks with Moscow they fear could end the war on terms that reward Russian President Vladimir Putin.
The spat has turned personal with Trump falsely claiming Zelensky is hugely unpopular among his own people and the Ukrainian leader saying Trump lives in a Russian "disinformation space".
Tech tycoon and Trump backer Elon Musk weighed in Thursday, saying Ukrainians "despised" their president and that the US leader was right to leave him out of talks with Russia.
Amid the war of words, Zelensky said Thursday he had held a "productive meeting" with US envoy Keith Kellogg in Kyiv.
"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-US relations benefit the entire world," he added.
However, there was no joint press conference or statements after the discussions, as would typically accompany such a visit.
Unacceptable
Trump is calling for Kyiv to hand over access to its mineral wealth as compensation for tens of billions of dollars in US aid delivered under his predecessor Joe Biden.
Zelensky rejected a deal proposed by Trump as it did not include "security guarantees" - Kyiv's key demand from its Western backers in any agreement with Russia to halt the fighting.
The feud marks a dramatic reversal from US policy under Biden, who lauded Zelensky as a hero, shipped vast supplies of arms to Kyiv and hammered Moscow with sanctions.
Trump has instead criticised Zelensky and blamed him for starting the war that began with Russia's full-scale invasion three years ago.
"A Dictator without Elections, Zelensky better move fast or he is not going to have a Country left," he wrote on his Truth Social platform on Wednesday.
Zelensky was elected in 2019 for a five-year term and has remained leader in line with Ukrainian rules under martial law, imposed as his country fights for its survival.
While Zelensky's popularity has fallen, the percentage of Ukrainians who trust him has never dipped below 50% since the conflict started, according to the Kyiv International Institute of Sociology (KIIS).
Shock at Trump attack
Trump's invective drew shock reactions from Europe.
German Chancellor Olaf Scholz said it was "wrong and dangerous" to call Zelensky a dictator.
The White House said France's Emmanuel Macron and Britain's Keir Starmer will visit Trump next week after European leaders held emergency summits in recent days over how to deal with Trump's threats to overhaul decades of transatlantic security ties.
The Kremlin, buoyed by its rapprochement with Washington, has hailed Trump's comments.
Russia, which for years has railed against the US military presence in Europe, wants a reorganisation of the continent's security framework as part of any deal to end the Ukraine fighting.
Putin said Wednesday that US allies "only have themselves to blame for what's happening", suggesting they were paying the price for opposing Trump's return to the White House.
Neither Kyiv nor European countries were invited to high-level talks between top diplomats from Russia and the US in Saudi Arabia earlier this week, deepening fears they are being sidelined.
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