US President Donald Trump has taken a tougher stance with Russia to get it to reach a peace deal in Ukraine.

He said on Monday the United States will send more weapons to Kyiv, including Patriot air defense systems.

He announced the plan during a meeting with NATO Secretary General Mark Rutte in the Oval Office. Trump said NATO member states will purchase the weapons and then deliver them to Ukraine.

Ukraine has been requesting more Patriot systems for months. Trump said some "top of the line" weapons should arrive "within days."

Rutte also said the support will mean that Ukraine gets "its hands on really massive numbers of military equipment, both for air defense, but also missiles, ammunition, etc."

Trump also threatened "severe" tariffs for Russia.

He said the rate would be 100 percent if Moscow does not make a deal with Kyiv within 50 days.

Ukrainian President Volodymyr Zelenskyy thanked Trump for his readiness to support his country, and continued efforts to stop the killing and establish a "lasting and just peace."