China's President Xi Jinping walks to a podium to deliver a speech at the opening ceremony of the annual Boao Forum in Boao, in southern China's Hainan province, Sunday, April 7, 2013. (Alexander F. Yuan/AP)

Responding to regional worries over North Korea’s bellicose threats, China on Sunday expressed concern and what appeared to be veiled criticism of its longtime ally.

“No one should be allowed to throw a region and even the whole world into chaos for selfish gains,” Chinese President Xi Jinping said at an economic forum in Hainan province. Avoiding mentioning North Korea by name, Xi said, “While pursuing its own interests, a country should accommodate the legitimate interests of others.”

Xi said the international community and its collective scrutiny should act as a platform for common development rather than an “arena where gladiators fight each other.”

On Sunday, China’s Foreign Ministry also issued a statement saying it was “seriously concerned” about the “continuously escalating tensions.”

The comments from China come on the heels of several days of escalating threats by North Korea against the United States and South Korea, including the possibility of nuclear attacks.

China — long seen as a key factor propping up the regime in Pyongyang — recently has shown signs of frustration after North Korea ignored its pleas not to carry out a recent nuclear test.

Chinese officials, who value stability above all else, are unlikely to abandon North Korea anytime soon. But sensing an opening amid Chinese frustrations, the Obama administration is trying to push Beijing to take a much stronger stance against the renegade country than it has in the past, U.S. officials have said in public and private comments in recent days.

“Clearly with the border they have, with the economic relationship that they have, they can do more,” Susan Rice, U.S. ambassador to the United Nations, said Friday at a women’s summit in New York. “What’s interesting about China’s stance now is that you can tell by the nature of their statements, by the nature of their actions, that, unlike in the past, they also are very much of the view that Kim Jong Un has gone too far, and that this now is a situation that has the potential to directly threaten their interests in the region — both economic and security.”

Meanwhile, three U.S. senators called on China to apply more pressure on North Korea.

“China does hold the key to this problem,” Sen. John McCain (R-Ariz.) said on CBS News’s “Face the Nation.”

“Chinese behavior has been very disappointing, whether it be on cyber­security, whether it be on confrontation in the South China Sea or whether their failure to rein in what could be a catastrophic situation,” he said.

Sen. Charles E. Schumer (D-N.Y.), who appeared on the same program, said he agreed with McCain.

“You know, the Chinese hold a lot of the cards here,” Schumer said. “They’re by nature cautious, but they’re carrying it to an extreme. It’s about time they stepped up to the plate and put a little pressure on this North Korean regime.”

Sen. Lindsey O. Graham (R-S.C.), appearing on NBC News’s “Meet the Press,” said: “I blame the Chinese more than anybody else. They’re afraid of reunification. They don’t want a democratic Korea next to China, so they’re propping up this crazy regime, and they could determine the fate of North Korea better than anybody on the planet.”

China’s statement Sunday, posted on the Web site of its Foreign Ministry, also seemed to dismiss as empty rhetoric North Korea’s warnings Friday that diplomats should think about leaving Pyongyang because of increasing tensions. Ministry spokesman Hong Lei said China’s Embassy in Pyongyang is operating normally.

In addition, China’s foreign minister called U.N. Secretary General Ban Ki-moon on Saturday night to discuss the situation, according to the Foreign Ministry.

In the conversation, Wang Yi repeated China’s oft-stated position that issues with North Korea can be solved only through dialogue, but he also said China is opposed to “any provocative words and actions from any party in the region and does not allow troublemaking at the doorsteps of China.”

Sean Sullivan in Washington contributed to this report.