Trump says S. Korea has approval to build nuclear-powered submarine

U.S. President Donald Trump, left, and South Korea's President Lee Jae Myung take their position for a family photo with other leaders upon their arrival for a special dinner hosted in honour of US.. President Donald Trump and state leaders at the Hilton Gyeongju hotel in Gyeongju on Wednesday. AFP-Yonhap

U.S. President Donald Trump said Thursday he has granted approval for South Korea to build a nuclear-powered submarine, adding the submarine will be built at shipyards in Philadelphia.

Trump wrote the message on his Truth Social account a day after he and President Lee Jae Myung agreed on the need for Seoul to secure fuel for nuclear-powered submarines during their summit held on the occasion of the Asia-Pacific Economic Cooperation events.

"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.

The approval was granted on the grounds that the U.S.-South Korea military alliance is "stronger than ever before," the U.S. president said, adding, "A great trip, with a great president of South Korea."

In a subsequent upload, Trump also said South Korea will be building its nuclear-powered submarine at the Philadelphia shipyards in Pennsylvania, the United States.

Trump arrived in South Korea on Wednesday for a two-day trip. He is scheduled to hold talks with Chinese President Xi Jinping on Thursday amid an escalating trade war with China.

The Philadelphia shipyards, which were bought by South Korea's Hanwha Group, have became a symbol of South Korea-U.S. cooperation in shipbuilding, with Seoul committing to help revive U.S. shipbuilding as part of the countries' recent trade deal.

"Shipbuilding in our country will soon be making a big comeback," Trump said on the social media account.

South Korea's nuclear fuel processing is regulated under a nuclear energy pact with Washington, which currently allows Seoul to enrich uranium below 20 percent with U.S. consent. South Korea needs a nod from the U.S. to secure enriched uranium fuel suitable for powering a submarine.

During talks with Trump the previous day, Lee said diesel-powered submarines have limited underwater navigation capabilities, restricting the South Korean military's ability to track North Korean or Chinese submarines, as he requested U.S. approval to secure fuel for nuclear-powered submarines.

On his social media account, Trump also announced that South Korea has agreed to pay $350 billion in return for a tariff reduction and to buy U.S. oil and gas "in vast quantities," saying investments from South Korean companies will exceed $600 billion.

How Trump reached the total sum remains unclear, but it appears to reflect South Korea's $350 billion investment pledge to the U.S., plus other investment promises made by South Korean firms so far.