By Mark Landler and Jane Perlez

New York Times News Service

BEIJING — President Donald Trump has often said he is counting on Xi Jinping to do the right thing with North Korea, alternately praising and prodding the Chinese leader about enforcing tougher sanctions, and even holding off on his campaign promises to get tough on trade in the hope Xi follows through.

To his frustration, however, Xi has proved adept at taking incremental steps while always stopping short of the more punishing measures that the White House believes would truly threaten the North Korean regime and force it to scrap its nuclear arsenal.

The pattern is a familiar one. Other U.S. presidents turned to China to solve the North Korea problem too and were generally disappointed. But with the North closing in on a nuclear missile that can hit the United States, there has never been more riding on this strategy.

Trump arrived in China on Wednesday for the stiffest test yet of his audacious bet: that by cultivating Xi and offering him concessions, like delaying punitive trade moves, he can persuade him to move against North Korea in a way that none of his predecessors have.

Yet it may be a gamble based on a fundamental misreading of Beijing’s influence over North Korea and especially its young leader, Kim Jong Un, under whom relations between the erstwhile allies have steadily deteriorated.

China, some analysts argue, just does not have the leverage over North Korea that Trump thinks it has.

“There are big differences in the way of thinking between the United States and China on North Korea,” said Yang Xiyu, a former Chinese Foreign Ministry negotiator on North Korea. “Trump thinks of North Korea too simplistically — that if China cuts off the oil, the nuclear issue will be solved.”

Trump, a senior administration official said, plans to call on Xi to cut off oil exports to North Korea, at least temporarily; to close North Korean bank accounts in China; and to send home tens of thousands of North Koreans who work in China.

Speaking in South Korea earlier Wednesday, Trump made an impassioned call for China and other countries to pull together to confront the North, which he described as a sinister regime that starved and terrorized its people — a tragic failed experiment in the “laboratory of history.”

“It is our responsibility and our duty to confront this danger together because the longer we wait, the greater the danger grows, and the fewer the options become,” he said to the National Assembly, South Korea’s parliament.

“To those nations that choose to ignore this threat or, worse still, to enable it, the weight of this crisis is on your conscience,” said Trump, who tried to travel to the heavily fortified demilitarized zone between the North and South but had to turn back after fog grounded his helicopter.