SEOUL — Presidents Trump and Lee Jae-myung are now on speaking terms. Prodded by Mr. Lee’s staff, Mr. Trump finally called Mr. Lee late Thursday, and, primed to stay up for the call, Mr. Lee accepted Mr. Trump’s congratulations for his election Tuesday.

They offered assurances that they would work to relieve the South of its worries about the high tariffs that Mr. Trump wants to impose on some of Korea’s biggest exports. They include steel, aluminum, and motor vehicles.

The focus on tariffs echoed a somewhat similar conversation that Mr. Trump had several days earlier with Communist China’s president, Xi Jinping, in which they agreed their negotiators would work to come to terms. One difference between the calls, however,  was that Mr. Trump and Mr. Xi talked for 90 minutes — 70 minutes more than the 20 minutes he had for Mr. Lee.

South Korean officials appeared relieved that they had found a slot in Mr. Trump’s schedule after the delay raised questions about  where Korea ranked in his priorities. Mr. Trump has said he would focus on the threat posed by Chinese expansionism in the Indo-Pacific, leaving the impression here that South Korea would face North Korea almost alone.

Messrs. Trump and Lee “agreed to encourage a tangible outcome in working-level talks” on tariffs on the way to “a mutually satisfactory agreement,” according to South Korea’s Yonhap News. As in Mr. Trump’s conversation with Mr. Xi, Messrs. Trump and Lee avoided specifics. The call was also noteworthy for skipping the military alliance with South Korea, where 28,500 American troops remain, as often stated by the Yank command, “ready to fight tonight.”

It’s suspected — but not acknowledged by either side — that one reason for delaying the call  was to clarify the scope of the conversation. Mr. Lee said the alliance “remains the foundation of Seoul’s foreign policy,” and a spokesman said his talk with Mr. Trump was conducted in “a friendly and candid atmosphere.” Neither, however, seemed to want to get into such sensitive issues as American troop strength or Korea’s contribution to the costs of keeping them here.

As a longtime leftist politician, Mr. Lee has described the Americans as “an occupation force” while Mr. Trump has hinted at withdrawing several thousand of our GIs. The leaders may, however, have revised their positions in view of North Korean leader Kim Jong-un’s alliance with President Putin, to whom he sent troops and arms for the war in Ukraine.

Messrs. Trump and Lee will have a chance to get to know each other better when Mr. Lee attends the G7 summit a week hence at  Alberta. Besides sitting down with Mr. Trump, he’ll also meet the leaders of the United Kingdom, Canada, France, Germany, Italy, and Japan as well as those of other countries invited as observers. Among them: Ukraine’s Volodymyr Zelensky, looking for another meeting with Mr. Trump.

The G7 “will mark Lee’s debut on the multilateral diplomatic stage,” said a spokesman. As for his phone call with Mr. Trump, the spokesman said they compared their experiences with assassination attempts and agreed “strong leadership is forged through hardship.”

On a lighter note, as reported by South Korea’s biggest newspaper, Chosun Ilbo, they “compared golf skills and floated the idea of a friendly round in the future — a nod to personal rapport and alliance solidarity.”