The US has hinted that it will resume joint military exercises with South Korea.

“We have no plans at this time to suspend any more exercises. We will work very closely, as I said, with the secretary of state and what he needs done,” Defense Secretary James Mattis said Tuesday.

The military drills have been suspended since Trump dropped the bombshell that the Pentagon would not conduct “war games” with South Korea following his meeting with North Korea’s Kim Jong-un in Singapore on June 12.

Before the summit, Korea-US joint military exercises had been regarded as an issue that had nothing to do with the dismantling of the North’s nuclear and missile programs. Their suspension was not included in the summit agreements. In this sense, Mattis’ remark signals that the military exercises will return to their former status.

The joint military drills must be conducted as part of their mutual defense treaty and considering the geopolitical factors of South Korea even after the North nuclear arsenal is removed. Although Trump said that the US would suspend them as long as it is negotiating “in good faith,” there was a great concern that the halt to the exercises would not only weaken the military strength of allies but also hurt the foundation of alliance.

Mattis’ words came days after Trump canceled Secretary of State Mike Pompeo’s planned visit to North Korea after receiving a belligerent letter from Pyongyang, effectively stalling negotiations to denuclearize the country. His remarks sound like a warning that the US may go back to a super-hardline stance if Pyongyang makes excessive demands or threatens the US without showing sincerity about its promise to dismantle its nuclear programs.

In the short term, Pyongyang is likely to resist US pressure, and Kim seems to have reached a crossroads -- to maintain dialogue with the US or choose a different course such as escalating criticism of the US or making no response.

Negotiations between the US and the North have effectively stopped, but at this stage we must avoid undermining dialogue itself.

A certain occasion to jumpstart the stalled negotiations is needed.

Ideally, North Korea must make the first move. It must send a message that it is ready to carry out its commitment sincerely to dismantle its nuclear arsenal. If it hasn’t decided to use brinkmanship to keep its nuclear arms, it should not threaten to scuttle the negotiations. If Kim is committed to denuclearizing his country, improving his ties with the US and ensuring the position of his regime, there is no reason to play a tug-of-war with Washington.

But the US must also not give up on negotiations easily. Though it says it is ready to talk when the North is ready and talks are expected to be productive, the Trump administration needs keep trying on its own to restart dialogue.

Negotiations to denuclearize the North are not a matter to be solved quickly. They can stop for a moment, but they must not stop for good. We should avoid returning to the pre-summit crisis.

Conditions for dialogue with North Korea came from sanctions and pressure based on close cooperation between the US and South Korea. Thus it is worrisome that the Seoul-Washington ties are showing signs of discord. The US prioritizes pressure on the North, while the South seeks to appease the North.

Undoubtedly, Pyongyang will drive a wedge between the US and South Korea if their relations show cracks. Washington is reportedly concerned about South Korea’s imports of North Korean coal and its hasty push for inter-Korean cooperation. Seoul must not rush joint projects with Pyongyang without progress in negotiations to denuclearize the North.

Contradictory as it may sound, the way to advance inter-Korean cooperation is to solve the nuclear issue by maintaining pressure on the North.