The official declined to comment on media reports that claimed the US offered a new proposal calling for raising Seoul's contribution to $1.3 billion.

Sources said that after US President Donald Trump in March rejected a 13 percent increase in cost-sharing contributions by South Korea compared to 2019, Washington may have lowered the initial $5 billion payment request and opted for something less.

Trump has argued South Korea needs to pay more for its own defense under the Special Measures Agreement (SMA). 

Others familiar with the talks said that despite numerous negotiations, the allies have yet to reach a deal on renewing the terms for Seoul's share of the cost to maintain some 28,500 American troops stationed on its soil.

The previous SMA expired at the end of last year, in which Seoul agreed to pay about $870 million. The absence of a new cost-sharing deal has led the US Forces Korea to place some 4,000 Korean employees on unpaid leave since April 1. (Yonhap)