The United States' closest allies in Asia seemed blindsided by President Donald Trump's latest outburst against North Korea, in which he threatened not just to act against Kim Jong Un's regime but to destroy an entire country of 25 million people.

In his maiden speech to the United Nations General Assembly Tuesday, Trump derided Kim as "rocket man" and said the United States would "totally destroy North Korea" if needed to protect its allies.

Those allies, Japan and South Korea, were silent on Trump's threat to bring war to their neighborhood, while China and Russia both warned that Trump risked fueling tensions.

China's nationalist Global Times newspaper ran a cartoon captioned "Bully pulpit" showing Trump holding a megaphone, shouting "America First," while the state-owned China Daily newspaper said Trump's speech was "full of sound and fury."

"Today's dangerous deadlock has been the result of Pyongyang's and Washington's persistent pursuit of their own interests in disregard of other countries' efforts to persuade the two antagonists to talk," the China Daily wrote in an editorial Wednesday morning. "His threat to 'totally destroy' [North Korea] if need be will, therefore, likely worsen the already volatile situation."

The silence from Japanese Prime Minister Shinzo Abe was particularly telling because he has been eager to agree with Trump's every utterance on dealing with North Korea. A spokesman for Abe, Motosada Matano, declined to comment on Trump's speech.

South Korean President Moon Jae-in, whom Trump accused of trying to "appease" North Korea by wanting to talk to the regime, has also been trying hard in recent weeks to show he is in synch with the American president.

Moon's spokesman pointedly avoided reacting to Trump's "total destruction" line, saying the speech underscored the urgency of dealing with North Korea and that Seoul believed Trump remained committed to peace.

"We believe he expressed a firm and specific stance regarding the important issue of maintaining peace and security now facing the international community and the United Nations," the spokesman, Park Soo-hyun, said in a statement.

"Also, we believe he clearly showed how seriously the U.S. government takes this issue by allocating an unprecedentedly long period of time to address the North Korean nuclear and North Korean issues in his U.N. address as a U.S. president," he said.

In his speech, Trump said that if Kim Jong Un's regime continued to threaten the United States and to destabilize East Asia, his administration was prepared to use force.

"The United States has great strength and patience, but if it is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea," Trump said.

Tensions between the Trump administration and Kim's regime have risen to new heights as North Korea has fired increasingly long-range missiles, including two that are theoretically able to reach the mainland United States, and detonated a hydrogen bomb.

As these tensions have mounted, Trump has warned Kim that he will feel the full "fire and fury" of the United States and that the United States was "locked and loaded."

Successive American administrations have long considered military options for dealing with North Korea highly problematic because the Kim regime could immediately retaliate by unleashing waves of conventional artillery trained on the South Korean capital, causing widespread devastation. The greater Seoul area is home to 25 million people, almost all of whom are within artillery range.

Analysts said that Trump's speech would ring alarm bells in the region.

"American rhetoric on North Korea has traditionally been quite restrained, they haven't been trying to match the North Korean rhetoric," said John Delury, an American professor of international relations at Yonsei University in Seoul.

"So there is a genuine concern here: is the Trump administration serious? Are they going to take us into the war we've avoided having since 1953?" he said, referring to the end of the Korean War.

Narushige Michishita, a Korea expert at the National Graduate Institute for Policy Studies in Tokyo, said that while the Abe government supported a hard line on North Korea, many Japanese people would also be concerned about Japan suffering during any conflict.

"The use of massive force would cause a huge amount of destruction in South Korea but Japan might also suffer," he said.

For China, the military option was "unimaginable" and "too costly," said Cui Zhiying, director of the Korean Peninsula Research Center at Tongji University in Shanghai.

"War is an unimaginable option and it should not be an option at all. It would hurt all parties, everyone on the peninsula and in the Northeast Asia region," he said. "Peaceful, diplomatic dialogue is the only way to solve this issue," he said.

Cui cautioned that military action from the United States would drag China into a difficult position as it would have no choice but react.

"China does not want to see war or chaos in North Korea," he said. "If the United States were to take military actions, China would have to react, simply because it's right on its doorstep."

In Russia, which has largely defended North Korea's interests although it supported the tightened sanctions, Trump's remarks were seen as a dangerous harbinger of instability.

Leading members of the Russian foreign policy establishment said that Trump's statements echoed his inexperience and were potentially dangerous for U.S. allies.

"Any military conflict means deaths of civilians. It is especially odd as the U.S. considers South Korea and Japan its allies, and they could be affected in case of a strike," Andrei Klimov, chairman of the foreign affairs committee in Russia's upper house of parliament, told the Interfax news agency in an interview Tuesday.

While Russian officials were initially excited about Trump's readiness to overturn the international order, a promised detente with Russia has failed to materialize, while bellicose rhetoric against Russian partners such as North Korea and Iran has stepped up.

At least "unlike his predecessors, he didn't put Russia among the main threats to mankind and even praised our country for cooperating with the Security Council on North Korea," Konstantin Kosachyov, another senior member of Russia's upper house of parliament, wrote in a post on Facebook.

But Trump's speech was "disappointing," said Kosachyov, who was in New York for this week's summit, particularly for "the extremely dangerous statements about the readiness to 'totally destroy North Korea' and exit the Iran deal as 'one of the worst for the U.S. and an embarrassment.' Plus Syria, Cuba and Venezuela as though they were the worst dictatorships in the history of mankind."