On Sunday, President Donald Trump claimed that Ukrainian President Volodymyr Zelenskyy “isn’t ready” to endorse a U.S.-drafted peace plan aimed at resolving the ongoing Russia-Ukraine conflict.

Trump’s remarks came after three days of negotiations between U.S. and Ukrainian officials, which concluded on Saturday, intended to reconcile differences over the proposal.

Speaking to reporters ahead of attending the Kennedy Center Honors, Trump suggested that Zelenskyy is slowing progress. “I am somewhat disappointed that President Zelenskyy has not yet reviewed the proposal, as of a few hours ago. His team appreciates it, but he has not,” Trump said.

He added, “Russia appears to be agreeable to it, but I am uncertain whether Zelenskyy shares that sentiment. His team is enthusiastic about it. However, he is not prepared.”

Trump’s relationship with Zelenskyy has been inconsistent since the former entered a second term, with the U.S. president repeatedly criticising the war as a misuse of American taxpayer funds. He has also encouraged Ukraine to cede territory to Russia to end a conflict that has lasted nearly four years and resulted in heavy casualties, according to his statements.