President Obama urged Chinese President Hu Jintao on Monday to help the United States ratchet up international pressure on North Korea as the White House sought to enlist China’s influence in its drive to halt Pyongyang’s plans to launch a long-range rocket next month.

In a 90-minute bilateral meeting that White House aides said was dominated by talk of how to deal with Pyongyang’s belligerence, Obama stressed to Hu that the North has repeatedly provoked the international community, despite efforts to keep the authoritarian nation in line.

“The Chinese indicated they take this very seriously. . . . They will work actively with us,” said Ben Rhodes, Obama’s deputy national security adviser for strategic communications.

The president’s plea to China comes as Pyongyang has proved brazenly unwilling to bow to the U.S. administration’s mix of economic sanctions and incentives. As Asia’s economic and military behemoth, China, which borders North Korea and acts as the impoverished country’s most reliable economic benefactor, has far more leverage.

Rhodes added that Obama told Hu to weigh Pyongyang’s pattern of bad behavior over time, rather than focusing solely on the recent provocations.

“Part of what is so distressing about this type of action is how regularly it is that North Korea chooses to engage in these types of provocative acts,” Rhodes said. “President Obama said we need to look at the bigger picture. There is new leadership in North Korea. Do they do the same the same thing the old leadership did or go down a different path?”

The session was just one in a series of bilateral meetings that Obama held with world leaders here as part of an international summit on nuclear security. But his message for Hu illustrated the ways in which the administration, running low on options, is increasingly turning to China for help on pressing foreign policy matters.

On Iran, Syria and Sudan, Washington has sought to enlist Beijing as a political ally to address complex, diverse issues, from nuclear ambitions to a brutal authoritarian crackdown to a potential famine.

The administration’s challenge, however, is complicated by its recent push to stand up to China on the economic front, where Obama has demanded that the world’s second-largest economy “play by the rules of the road” — namely, respecting intellectual property rights, revaluing its currency to balance trade and loosening control of its near-monopoly on rare-earth materials used in the production of many common electronic goods.

Rhodes called the relationship “very large and complex.”

When asked at a news conference Sunday what he would request of Hu, Obama said: “It’s not in anybody’s interest to see a nuclearized [Korean] Peninsula. The Chinese say they agree with that. The question then is, given that they have more influence and closer diplomatic relations with North Korea than any other country on Earth, what are they doing to help guide or encourage North Korea to take a more constructive approach?”

During his trip here, Obama has sought to dramatize North Korea’s isolation by comparing the impoverished nation’s withdrawal from the outside world with the course taken by South Korea and China, countries the president praised for engaging the international community on a path to extraordinary economic growth.

At Hankuk University of Foreign Studies on Monday, Obama delivered an impassioned speech, calling for a drawdown of nuclear stockpiles and urging North Korea and Iran to pursue a path of diplomacy to lessen tension over their nuclear ambitions.

Challenging doubters of his vision, Obama described a South Korea that is among the most technologically sophisticated countries on Earth, and he delighted the students by name-checking Korea’s most popular social media networks, Me2Day and Kakao Talk.

“Come to this country, which rose from the ashes of war . . . turning rubble into gleaming cities,” Obama said. “Stand where I stood yesterday, along a border that is the world’s clearest contrast between a country committed to progress . . . and a country that leaves its own citizens to starve.”

Obama called Koreans “one people” and compared their future to that of Germany, which was divided after World War II but reunified half a century later.

“So, too, on this divided peninsula,” Obama declared. “The day all Koreans yearn for will not come easily or without great sacrifice. But make no mistake, it will come.”

Still, China is unlikely to be swayed by oratory alone. Beijing has long resisted calls to criticize Pyongyang, disputing the amount of influence it has in the North.

“I think China’s influence is quite limited,” said Chung Jae-ho, a professor of international relations at Seoul National University. “Officials in Beijing say it, and I think they mean it. I don’t mean China has no power at all — it does have power, given the dependence Pyongyang has. But that dependence can be translated into power only once” — that is, if China were to fundamentally take away its support of North Korea.

Hu also had a request for Obama. The Chinese leader called on the White House to maintain a dialogue with Pyongyang’s young new ruler, Kim Jong Eun, Beijing’s Xinhua news agency reported.

China wants the United States and North Korea to continue talks and to “honor the consensus reached between them” on Feb. 29, when the North pledged to stop weapons testing and Washington agreed to deliver food aid, Xinhua said. Obama administration officials have indicated that the North’s rocket launch would nullify that deal.

Asked about Hu’s request, Rhodes said: “We made it clear we could not foresee going forward with an agreement if North Korea engages in this missile launch. We are open to a dialogue if North Korea keeps its commitments.”