US President Donald Trump said on Thursday that he has granted South Korea the approval to to build a nuclear-powered submarine in the United States.

The remarks come as Trump is in South Korea, where he met with President Lee Jae Myung.

Trump's announcement also came ahead of his meeting with Chinese President Xi Jinping. China is also in possession of nuclear submarines.

"I have given them approval to build a Nuclear Powered Submarine, rather than the old fashioned, and far less nimble, diesel powered Submarines that they have now," Trump wrote on his Truth Social platform.

He added that the submarine would be built in the US city of Philadelphia.

"Shipbuilding in our Country will soon be making a BIG COMEBACK," Trump added.

South Korea to invest in US shipbuilding

South Korea's president is said to have asked Trump to "make a decision to allow us to receive fuel for nuclear-propelled submarines."

Such submarines would help South Korea better track North Korean and Chinese vessels for longer periods.

"We are not proposing to build submarines armed with nuclear weapons; rather, diesel submarines have inferior submerged endurance, which limits our ability to track North Korean or Chinese submarines," Lee told Trump.

Nuclear submarine technology is widely regarded as one of the most sensitive and highly guarded technologies in the United States.

There were no concrete details about the size or cost of the project. As part of talks with Trump, South Korea revealed that it had committed $150 billion (€130 billion) to invest in America's shipbuilding capacity.

Edited by: Dmytro Hubenko