• 3,800 North Koreans have been killed or wounded fighting alongside Russia, Volodymyr Zelenskyy said.
• But Ukraine's president told the Lex Fridman podcast that hundreds of thousands more could arrive.
• The estimate came amid a discussion of the danger to Europe if the US leaves NATO.

Ukrainian President Volodymyr Zelenskyy said in a podcast interview released Sunday that 3,800 North Korean soldiers had been killed or wounded in Russia's Kursk region to date.

Zelenskyy's figure suggests that a third of the North Korean troops brought over to fight alongside Russia have been taken out of action.

"12,000 has arrived. Today, 3,800 killed or wounded," he told podcaster Lex Fridman, but he cautioned that North Korea could send many more, giving a figure as high as half a million troops.

Estimates of North Korean casualties have varied since intelligence agencies reported in October that it was sending troops to help Russian President Vladimir Putin defend territory seized by Ukraine in the summer.

In late December, the White House estimated that more than 1,000 North Koreans had been killed or wounded in the space of a single week, amid mass dismounted attacks.

And in his nightly address on Saturday, Zelenskyy said that the Russian army had lost "up to a battalion of infantry, including North Korean soldiers and Russian paratroopers," in fighting in the village of Makhnovka in Kursk.

Concerns for Europe

Zelenskyy offered the latest casualty figures as part of a broader argument about the dangers to Europe if the US retreats from NATO.

President-elect Donald Trump has long been critical of NATO and the defense spending of some of its members, leading to concerns that he could slash support for the alliance or even walk away.

Zelenskyy said that if Trump decides to leave NATO once back in office, "Putin will destroy Europe."

He also argued that European countries are much less willing and able to raise massive armies compared to an autocracy like North Korea.

While Ukraine has around 980,000 military personnel, the militaries of its European allies are a fraction of the size, Zelenskyy said.

"Can Europe bring people together? No," he said. "Will Europe be able to build an army consisting of two to three million people? No, Europe will not want to do this."

Dmytro Ponomarenko, Ukraine's ambassador to South Korea, told Voice of America in November that the number of North Korean troops aiding Russia could soon reach 15,000, with troops rotated out every two to three months.

That could mean about 100,000 North Korean soldiers serving in Russia within a year, he added.