SEOUL, South Korea >> President Moon Jae-in of South Korea warned today that North Korea would face stiffer sanctions if it resumed weapons tests, while crediting President Donald Trump with helping force the North to resume dialogue and strike a broader agreement to improve Korean ties.

“I am giving a lot of credit to President Trump,” Moon said at a nationally televised news conference a day after the two Koreas forged their agreement during border talks. “I am expressing my gratitude.”

The White House said that Trump and Moon had spoken and “underscored the importance of continuing the maximum pressure campaign against North Korea,” adding that Trump “expressed his openness to holding talks between the United States and North Korea at the appropriate time, under the right circumstances.”

Moon’s comments and his conversation with Trump suggested a tactful maneuver by the South Korean leader to stroke the ego of Trump, who has claimed credit for the inter-Korean dialogue, while easing fears in Washington and among his conservative critics at home that in his eagerness for dialogue, he may be toao accommodating to North Korea’s leader, Kim Jong Un.

In a post on Twitter last week, Trump asserted that North Korea had gone to the negotiating table because he had been “firm, strong and willing to commit our total ‘might’ against the North.” Moon agreed Wednesday that Kim’s decision to start a dialogue with the South could be a sign that the Trump administration’s policy of applying maximum sanctions and pressure was working.

And he said South Korea and its allies must seize on the North’s renewed appetite for negotiations to persuade it to join broader talks involving the United States over how to end its rapidly advancing nuclear weapons program — an approach the North’s chief delegate to the border talks angrily rejected Tuesday.

Otherwise, North Korea made a surprisingly conciliatory gesture during the talks, promising to send a delegation of athletes, cheerleaders and journalists to the Winter Olympics being held next month in the South Korean town of Pyeongchang. The North also agreed to more talks with the South, including a dialogue between their militaries, to ease tensions and improve ties.

This week’s talks, in the border village of Panmunjom, were the first governmental dialogue between the Koreas in more than two years, and the agreements they produced were hailed as a welcome reprieve for South Koreans after a year of talk of war over the North’s nuclear and long-range missile programs.

But they also came amid concern that Moon might end up facilitating Kim’s strategy of fracturing the U.S.-led sanctions campaign and driving a wedge between Seoul and Washington.

Addressing such concerns, Moon said there was a limit to how far the two Koreas could go in improving ties if North Korea did not move toward dismantling its nuclear weapons program.

“The two issues — improving inter-Korean relations and resolving the North Korean nuclear issue — cannot be separated,” Moon said. “If the North provokes again or does not show sincerity on revising its nuclear problem, the international community will continue to apply even stronger sanctions and pressure.”

“My government has no intention of easing sanctions unilaterally,” he added, dismissing speculation that he might lift some of the sanctions imposed by his conservative predecessors, like the closing of a joint factory park in the North Korean town of Kaesong.

But Moon, a vocal critic of Washington’s plan to use military force to resolve the North’s nuclear threat, reiterated that the ultimate goal of sanctions and pressure must be to force North Korea to negotiate. He emphasized that his top national security and foreign policy goal was to prevent war on the Korean Peninsula.

Since he took office last May, Moon has faced detractors at home, especially older and conservative South Koreans who fear he may concede too much to the North as he doggedly champions talks. Such concerns have persisted even as Moon has moved to build more powerful missiles and get new weapons from the United States to counter the North’s nuclear threat.

Conservative South Koreans, as well as U.S. policymakers, remain deeply skeptical of Kim, the North Korean leader, who has accelerated the pace of nuclear and missile tests since taking power six years ago.

In a New Year’s Day speech, Kim proposed dialogue with the South to discuss his country’s participation in the Pyeongchang Olympics, which Moon has called for repeatedly. But he wants North Korea to be accepted as a nuclear weapons state, even boasting in his speech that he now had a “button” in his office to launch nuclear missiles at the U.S. mainland. At the same time, he urged Koreans on both sides to work together for peace.

During the border talks Tuesday, the North’s top negotiator, Ri Son Kwon, categorically rejected the South’s attempt to discuss the nuclear issue, calling it “absurd” and warning that it could derail efforts to improve inter-Korean relations. He said North Korea’s nuclear weapons were not built to attack South Koreans, Chinese or Russians, but were “aimed solely at the United States.”

For decades, North Korea has refused to discuss its nuclear weapons program with the South, insisting that it is an issue to be addressed only by it and the United States.

On Tuesday, Canada and the United States will host a meeting in Vancouver, British Columbia, of foreign ministers from countries that supported the United Nations-backed effort to repel North Korean forces after the 1950 invasion of South Korea. China said Wednesday that it would not attend the meeting because not all of the main parties to the conflict would be in attendance.

© 2018 The New York Times Company