South Korea and the US are expected to announce the suspension of "large-scale" military drills this week, with the provision that they would restart if North Korea failed to keep its promise to denuclearise, news agency Yonhap says.
Citing an unnamed government source, the South Korean news agency said on Sunday the suspension was likely to affect only major joint exercises, not more routine military training.
US President Donald Trump surprised officials in Seoul and Washington when he pledged to end "war games" after his summit with North Korean leader Kim Jong-un in Singapore last week.
Trump said via Twitter on Sunday that it was his initiative to suspend the military drills, a step North Korea has long sought.
"Holding back the 'war games' during the negotiations was my request because they are VERY EXPENSIVE and set a bad light during a good faith negotiation," the US president wrote. "Also, quite provocative. Can start up immediately if talks break down, which I hope will not happen!"
Immediately after the announcement on June 12, US forces in Korea said they had received no guidance on stopping any drills, and South Korean officials said they were trying to figure out which exercises Trump was referring to.
However, in a sign Seoul may be open to suspending drills, South Korean President Moon Jae-in said on Thursday his government would need to be flexible when it came to applying military pressure on North Korea if it was sincere about denuclearisation.
Moon said South Korea would carefully consider joint military drills with the US and he asked his officials to co-operate with the US on the issue, his office said in a statement at the time.
At a Senate hearing on Thursday, Trump's nominee to be ambassador to South Korea, retired Admiral Harry Harris, backed the idea of a "pause" in major military exercises. He said his understanding was that any suspension would involve only major military exercises and that regular training of US forces in South Korea would continue, although final decisions were up to the Department of Defence.
The US-South Korean exercise calendar hits a high point every year with the Foal Eagle and Max Thunder drills, which both wrapped up last month.
Yonhap also reported on Sunday that during military talks between the two Koreas on Thursday, South Korean officials asked their northern counterparts to relocate artillery 30 to 40 kilometres away from the heavily fortified military demarcation line that divides the two countries.
The South's defence ministry denied it made such a request, Yonhap said.