South Korea's acting President Han Duck-soo said on Monday President Donald Trump appeared to have directed talks on tariffs to begin immediately with South Korea, Japan and India, Yonhap News Agency reported.

Han also said he expected there to be a video meeting between the U.S. and South Korean officials on the proposed Alaska LNG project soon, Yonhap said.

The acting president had explained in detail South Korea's stance on tariff negotiations to Trump and the U.S. president had been satisfied, Han was quoted as saying during a meeting of the economic security strategy task force.

He also vowed to talk directly with Trump again if necessary as part of efforts to find common ground in cooperation between the countries over liquefied natural gas (LNG) and shipbuilding, Yonhap reported.

Last week, South Korea's trade and industry minister said potential cooperation with Washington in the shipbuilding sector was a "very important card" in negotiating over tariffs.

South Korea has shown interest in the Alaska LNG project, which is part of Trump's bid to boost U.S. gas exports, but any participation would hinge on discussions with Washington, the minister said, noting the project might struggle to achieve profitability.

Kim Hong-kyun, Seoul's first vice foreign minister, told parliament on Monday that the Trump administration has yet to propose talks to negotiate defense costs related to U.S. troops stationed in the country.

South Korea was, however, preparing for various scenarios, he said.

Trump has said he talked to Han last week about South Korea's payment for "big time" U.S. military protection, signaling that defense costs could be part of a broader deal not only about tariffs and trade.