Stalled negotiations on South Korea’s share of the cost for stationing US troops here should not be allowed to go adrift further, as it could damage the alliance between the two countries on the path to removing nuclear threats from North Korea.

Despite 10 rounds of discussions last year, the two sides have not agreed on the amount and other terms of Seoul’s payment for the upkeep of the 28,500-strong US Forces Korea. A five-year cost-sharing agreement expired at the end of last year.

South Korean Foreign Minister Kang Kyung-wha told reporters earlier this week that there is a “very big” difference between the allies on sharing USFK cost and declined to comment on the exact amount Washington has requested and Seoul is ready to accept.

US President Donald Trump’s administration demands that Seoul sharply increase its burden from the current 960 billion won ($852 million) a year. Reports say it has recently sent Seoul a final notice that South Korea’s payment must be above $1 billion and the burden-sharing accord should be renegotiated on a yearly basis.

Late last month, US Ambassador to Seoul Harry Harris called on South Korea’s national security adviser Chung Eui-yong, possibly to convey a firm message from Washington. Furthermore, Harris, a retired admiral who once commanded US forces in the Pacific, contributed an article to a local daily, in which he said South Korea “should do significantly more to share the burden” of defending itself.

Washington’s firm stance apparently reflects Trump’s will to get South Korea and other US allies to pay more of their defense cost. He has expressed his willingness to withdraw US troops from allies whose contributions fall short of his expectations.

Many here might view the Trump administration’s approach as high-handed and feel negatively about the US leader’s tendency to calculate the value of alliances in economic terms.

President Moon Jae-in’s government in Seoul seems to worry that accepting the US demand would cause a backlash from left-leaning lawmakers and progressive groups. It appears to be somewhat bound by a self-imposed psychological limit of 1 trillion won in sharing the cost of stationing US troops here.

But the Moon government needs to be more flexible and forward-looking in order to prevent a tug of war over the level of cost sharing -- which is hard to be set by concrete standards agreed on by both sides -- from undermining the alliance crucial for peace and stability on the Korean Peninsula.

Such an attitude is needed to avoid making it easier for Trump to use the withdrawal of US troops as a bargaining chip to freeze the recalcitrant regime’s nuclear weapons program and remove its long-range missiles while shelving its complete denuclearization. Trump’s second summit with North Korean leader Kim Jong-un is expected to take place next month.

Trump is prohibited by law from reducing the number of US soldiers here to below 22,000 without congressional approval. This means that he would be free to cut the troop size by about 6,000 if he decides to do so.

The North seemed to be trying to drive a wedge between Seoul and Washington when the organ of its ruling party criticized the US on Wednesday for demanding a rise in Seoul’s share of the cost for US military presence. The Rodong Sinmun called the demand “anachronistic,” referring to a series of inter-Korean deals reached last year to ease military tensions on the peninsula.

A weaker alliance between Seoul and Washington following the pullout of US troops would place South Korea in a more vulnerable position in dealing with China and Japan. Since Moon took office in 2017, Seoul has seen its relations with Tokyo strained over historical issues and its ties with Beijing overshadowed by the restored bond between China and North Korea.

The withdrawal of US troops could also have a significantly negative effect on the country’s economy, as it could deepen investors’ concerns about security conditions.

The Moon administration would be wise to increase Seoul’s payment closer to the figure suggested by Washington while trying to ensure the cost-sharing arrangement will be renegotiated on a longer-term basis. It is a reasonable argument that the alliance would unnecessarily be put on unstable footing if negotiations on revising the accord are held every year as the US demands.

Hopefully, accepting Washington’s request regarding defense cost may bolster Seoul’s case in other areas of mutual concern.