North Korea fired at least two short-range projectiles Tuesday, just a day after it expressed willingness to resume denuclearization talks with the US in late September.

The firings -- the 10th such launch by the North this year -- seem designed to strengthen its negotiating hand ahead of the resumption of talks that have stalled since February’s rupture of a summit between US President Donald Trump and North Korean leader Kim Jong-un.

Trump and Kim agreed to resume working-level discussions within several weeks when they met for a third time at the inter-Korean border village of Panmunjom in June. Pyongyang has since shunned coming to the negotiating table despite Washington’s repeated calls for the recalcitrant regime to return to talks on scrapping its nuclear arsenal in return for economic rewards and security assurances.

North Korea’s First Vice Foreign Minister Choe Son-hui said in a statement Monday that the North was ready to “sit with the US side for comprehensive discussions of the issues we have so far taken up at the time and place to be agreed late in September.” She also demanded Washington come up with new proposals “based on the calculation method acceptable to us,” warning that if it failed to do so, North Korea-US dealings might come to an end.

Choe’s statement may be seen as a change in Pyongyang’s attitude.

It has apparently believed that it would gain a negotiating advantage by delaying a deal with Washington in the lead-up to next year’s US presidential election. As recently as on Aug. 31, Choe said that expectations of dialogue with the US are gradually disappearing.

But the latest signals from the Trump administration seem to have the North judging that a further refusal to come to the negotiating table could cause the situation to change to its disadvantage.

The top US negotiator with Pyongyang last week suggested that Washington might allow its two key Asian allies -- South Korea and Japan -- to possess their own nuclear weapons to counter threats from a nuclear-armed North Korea. “At what point will voices in South Korea or Japan and elsewhere in Asia begin to ask if they need to be considering their own nuclear capabilities?” asked Stephen Biegun, US special representative for North Korea, in a speech at the University of Michigan.

His question was apparently addressed beyond the audience in attendance to China, which holds decisive leverage on the North as the only major ally and economic benefactor of the isolated regime.

It is notable that Choe’s offer came after Chinese Foreign Minister Wang Yi made a three-day visit to Pyongyang last week. Wang appeared to have conveyed Beijing’s wish to restart denuclearization talks as part of the efforts to ease Beijing’s standoff with the Trump administration over a broadening range of issues.

North Korea might also have judged that a string of launches of short-range ballistic missiles and rocket systems over the past months would be enough to bolster its negotiating position. Such test-firings stopped short of breaching Kim’s agreement with Trump not to test long-range ballistic missiles, but demonstrated the North’s enhanced capabilities to strike targets, including US military bases, in South Korea and Japan.

Trump appeared to be in a positive mood when he responded to the North Korean offer Monday, saying that “having meetings is a good thing, not a bad thing.” A day earlier, US Secretary of State Mike Pompeo said he thought Trump would be “very disappointed” if Kim did not return to the negotiating table or conducted missile tests inconsistent with their previous agreements.

Chances seem not so high that the next working-level talks would produce substantial progress. Pyongyang is unlikely to agree on a concrete road map for its complete denuclearization while calling for sanctions relief.

Pyongyang has been attempting to secure a last-minute deal with the US that gives it both status as a nuclear-armed state and a significant easing of international sanctions.

Trump may be willing to reach a half-baked deal with Pyongyang in the course of his reelection campaign. Such a concern has been heightened by Tuesday’s dismissal of his national security adviser, John Bolton, who has long taken a tough stance on handling the North.

There still remains the possibility that denuclearization talks will eventually be derailed, getting Trump to switch back to a confrontational mode.

South Korean President Moon Jae-in’s administration, which has stuck to a rosy view of Pyongyang’s denuclearization, should be on alert over a possible compromise between Trump and Kim, while preparing for the possibility of a breakdown in US-North Korea talks.