In this file photo dated Oct 19, 2022, flags of South Korea and the United States flutter before a joint river-crossing drill between South Korea and the United States in Yeoju, South Korea. (PHOTO / AP)

SEOUL - South Korea expects no fundamental shift in relations with the United States even if US voters elect a new president, but hopes to make progress on defense cost-sharing talks and other issues this year, a senior presidential official said.

The official, speaking with a small group of journalists on Monday, said that South Korea does not devise its policy based on predictions on the US presidential election in November, but that both sides will try to advance efforts to bolster security partnerships before that.

The allies have agreed to launch early talks on sharing the cost of keeping US troops in South Korea, and will accelerate discussions to boost Seoul's say in operating US extended deterrence, including American nuclear umbrella, the official said.

ALSO READ: US, ROK reach agreement on defense cost sharing

If Donald Trump is elected, South Korea will work with his government, but the alliance will remain unchanged in part because of solid support from the US Congress for greater bilateral cooperation and a trilateral partnership involving Japan, said a South Korean senior presidential official

"There is an incentive for the Biden administration to work more actively on the issues as it wraps up its first term this year," the official said. "We share the need to make some achievements, and that's why both sides have agreed to begin the defense cost-sharing negotiations and complete the work on extended deterrence."

The US State Department did not immediately respond to a request for comment, but has said that its delegation visited South Korea in December to discuss the defense cost-sharing deal and would work with Seoul to prepare for talks on the next agreement.

Former president Donald Trump, favored to be the Republican candidate in the election, had accused South Korea, a key Asian ally, of "free-riding" on US military might, called for stopping what he called "expensive" war games, and demanded that Seoul pay as much as $5 billion a year for the US deployment.

READ MORE: ROK agrees to 13.9% increase in its share of cost for US troops

If Trump is elected, South Korea will work with his government, but the alliance will remain unchanged in part because of solid support from the US Congress for greater bilateral cooperation and a trilateral partnership involving Japan, the official said.

"There's a difference between what you say as a candidate and what you actually do as responsible head of state who carries out global policies," the official said. "The president might change every four years, but the US Congress is never fickle."