ISTANBUL

US President Donald Trump said Monday he discussed limiting nuclear weapons with Russian President Vladimir Putin, including plans to involve China in denuclearization efforts.

"We are talking about limiting nuclear weapons. We will get China into that," Trump told reporters in the Oval Office. "We have the most. Russia has the second most, and China has third."

He said Beijing is behind Washington and Moscow but underlined its growing nuclear capabilities. "China is way behind, but they will catch us in five years," he said.

Russia and the US together possess around 90% of all nuclear weapons, according to the Stockholm International Peace Research Institute in Stockholm, Sweden. It estimates that China currently has at least 600 nuclear warheads.

“I think the denuclearization is a very ... big game, but Russia's willing to do it, and I think China's going to be willing to do it,” Trump told reporters separately while hosting South Korea's new President Lee Jae-myung.

Stating that the proliferation of nuclear weapons cannot be allowed, Trump said: “We have to stop nuclear weapons. The power is too great.”

Trump emphasized that Putin's Alaska visit on Aug. 15 demonstrated his commitment to negotiations. "The fact that he went to Alaska, our country, I think, was a big statement that he wants to get it done," he said.

However, he expressed frustration with Russia's ongoing attacks in Ukraine, saying: "Every conversation I have with him is a good conversation. And then, unfortunately, a bomb is loaded up into Kiev ... and then I would get very angry," Trump said.