Trump, who campaigned on an "America First" foreign policy, has said previously that he wanted to strike a deal between Kyiv and Moscow, without giving details, and end bloodshed in the Middle East.

"We have to get back to a great country with low taxes and a strong military. We're going to fix our military, we did once and now we're going to have to do it again," he said Thursday at a gala organized by the America First Policy Institute at his Mar-a-Lago resort in Palm Beach, Florida.

"We're going to work on the Middle East and we're going to work very hard on Russia and Ukraine. It's got to stop," Trump added.

He also criticized the "big chunk" of US spending on Afghanistan, from where American troops withdrew in 2021 after two decades of fighting an insurgency by the Taliban, which returned to power that year.

Trump's re-election has the potential to upend the almost three-year conflict between Russia and Ukraine, throwing into question Washington's multibillion-dollar support for Kyiv, which is crucial to its defense.

The Republican said on the campaign trail that he could end the fighting within hours and has indicated he would talk directly with Russian President Vladimir Putin.

Trump has not said how he intends to strike a peace deal on Ukraine or what terms he would propose.

Trump has nominated Fox News host and National Guard veteran Pete Hegseth to lead the world's most powerful military as defense secretary, despite a slim CV.

If confirmed by the Senate, Hegseth would command around 3.4 million soldiers and civilians, and oversee an annual budget of about $850 billion.

The president-elect has entrusted Elon Musk, the world's richest man, with the task of proposing cuts of $2 trillion from the federal government's $7 trillion budget.