The U.S. administration never tells its partners what weapons should be transferred to Ukraine, Spokesperson for the White House National Security Council John Kirby has said on Friday.

"We have never dictated to another partner what they can or can't give or on what timeline," he said, answering a question at a briefing about how Washington treats the idea of transferring Polish MiG-29s to Ukraine.

In addition, Kirby said the United States does not currently train Ukrainian pilots on U.S. combat aircraft. "there's no training underway right now because there is no – there's no commitment by the United States to provide fighter aircraft [to Ukraine]," he said.