Military options to stop North Korea's nuclear ambitions are still being mentioned in the United States despite the growing reconciliatory mood, an opposition leader said Monday.

Yoo Seong-min, co-leader of the centrist Bareunmirae Party, made the remarks following his recent weeklong trip to Washington, where he held talks with former and current US officials and scholars.

"The atmosphere in Washington vis-a-vis military options against North Korea was different from ours ... (The US) still made references to the possibility of military options," Yoo said during a party meeting.

Yoo Seong-min, co-leader of the minor opposition Bareunmirae Party, speaks during a party meeting at the National Assembly in Seoul on March 26, 2018. (Yonhap)
"Many former and current (US) officials and scholars said South Korea has underestimated the possibility of military options," he said.

The talk of US military actions such as preventive strikes against Pyongyang has recently dwindled due to a peace mood forged during last month's winter Olympics in the South as well as agreements to hold summits between the Koreas and between the US and the North.

But that talk has reemerged as US President Donald Trump has tapped security hawk John Bolton, who has championed military action against Pyongyang, as his top security advisor and hardliner Mike Pompeo as his new secretary of state.

"Our (South Korea's) security goal is to prevent war and achieve the complete denuclearization of North Korea ... But should the negotiations between the US and the North flounder, the possibility of a military option would still remain a big task for us," Yoo said.

Yoo also pointed to a conflict among hawks and doves within the Trump administration as a potential "big risk" for Seoul's policy on Pyongyang's denuclearization.

"As the secretary of state and the National Security Council advisor have been dismissed, the possibility has increased that a (security decision) will be made based on what President Trump wants," he said.

"I have come to the conclusion that the Seoul government has to seek to reduce risks from the US given that the US government's decision-making (process) is uncertain and difficult to predict," he added.(Yonhap)