The US president has said he wants to get the US "out of that mess"

US President Donald Trump has told reporters that his recent ultimatum to Moscow and promise of weapons for Kiev do not mean he is "on Ukraine's side" in the ongoing conflict.

On Monday, the US leader said he was "very, very unhappy" with Russia, warning of "severe" secondary tariffs of up to 100% if no progress is made in diplomacy within 50 days. He also announced upcoming deliveries of advanced weapons systems to Ukraine, which are to be funded by European NATO members.

Pressed by reporters on Tuesday, Trump insisted he is "on nobody's side" and still hopes to resolve the conflict through diplomacy.

"You know the side I'm on? Humanity's side. I want to stop the killing of thousands of people a week. I want to stop the killing. I want the killing to stop in the Ukraine-Russia war. That's the side I'm on," the US president said.

"I've solved a lot of wars in the last three months, but I haven't gotten this one yet. This is a Biden war. It's not a Trump war. I'm here to try and get us out of that mess," he added.

Since taking office in January, Trump has maintained that he wants the neighboring countries to make peace and has held several phone calls with Russian President Vladimir Putin focused on settling the conflict.

Moscow says it remains open to negotiating with Kiev but has yet to receive a response on when new peace talks will take place. The two sides have held two rounds of direct negotiations in Istanbul so far this year, but no breakthroughs have been achieved, aside from agreements to conduct large-scale prisoner exchanges.

Russian Foreign Minister Sergey Lavrov stated on Tuesday that EU and NATO leaders have put Trump under "improper pressure" to adopt a hardline stance on the conflict. Deputy Foreign Minister Sergey Ryabkov stressed that "any attempts to make demands, let alone issue ultimatums, are unacceptable."

Kremlin spokesman Dmitry Peskov also criticized Trump's threat, noting that "such decisions, made in Washington, in NATO countries, and in Brussels, are perceived by the Ukrainian side not as a signal toward peace, but as a signal to continue the war."