The United States and South Korea will go ahead with joint military drills next week, the top U.S. military official said on Thursday, resisting pressure from North Korea and its ally China to halt the contentious exercises.
North Korea's rapid progress in developing nuclear weapons and missiles capable of reaching the U.S. mainland has fueled a rise in tensions in recent months.
U.S. President Donald Trump warned North Korea last week it would face "fire and fury" if it threatened the United States, prompting North Korea to say it was considering plans to fire missiles at the U.S. Pacific territory of Guam.
Annual military drills involving tens of thousands of U.S. and South Korean troops are due to begin on Monday. North Korea views such exercises as preparations to invade it.
China, North Korea's main ally and trading partner, has urged the United States and South Korea to scrap the drills in exchange for North Korea calling a halt to its weapons programs.
Joseph Dunford, chairman of the U.S. Joint Chiefs of Staff, said the exercises were "not currently on the table as part of the negotiation at any level".
"My advice to our leadership is that we not dial back our exercises. The exercises are very important to maintaining the ability of the alliance to defend itself," Dunford told reporters in Beijing after meeting his Chinese counterparts.
"As long as the threat in North Korea exists, we need to maintain a high state of readiness to respond to that threat," he said.
Fan Changlong, a vice chairman of China's powerful Central Military Commission, told Dunford that China believed the only effective way to resolve the issue was through talks.
"China believes that dialogue and consultations are the only effective avenue to resolve the peninsula issue, and that military means cannot become an option," China's Defense Ministry cited Fan as saying.
Asked to respond to the criticism that China's "dual suspension" proposal to halt the U.S. military drills with South Korea and the North's missile tests made a false equivalence between the two, Foreign Ministry Spokeswoman Hua Chunying said it was the most realistic and achievable solution.
"To ease the tense situation created by tit-for-tat escalations, to halt this vicious cycle, there is a need to put aside the dispute over who goes first and who goes second," she said, speaking at a regular briefing.
North Korea has in the past fired missiles and taken other steps in response to exercises.
Arriving in Tokyo on Thursday, the new U.S. ambassador to Japan, William Hagerty, said America's ability to defend itself and its allies against North Korea was "beyond question".
He reaffirmed Washington's commitment to its alliance with Tokyo, a security pact he described as "ironclad."
Allies the United States and South Korea remain technically at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.
Russia called on the world to show restraint, saying it was vital to avoid doing anything that would result in reaching a "point of no return".
"Any attempt to resolve the problem over the Korean Peninsula by force will lead to a massive tragedy and enormous loss of life," Maria Zakharova, a spokeswoman for the Russian Foreign Ministry, told briefing in Moscow.
North Korea conducted what it said were two successful intercontinental ballistic missile (ICBM) tests in July, further raising tension after its four and fifth nuclear tests in 2016.
U.S. and South Korean officials have for months been expecting a sixth nuclear test.
"I would consider that North Korea is crossing a red line if it launches an intercontinental ballistic missile again and weaponizes it by putting a nuclear warhead on top," South Korean President Moon Jae-in said at a news conference in Seoul marking his first 100 days in office.
Moon has repeatedly urged North Korea not to "cross the red line" but had not previously elaborated what that would constitute.
Trump had promised to seek negotiations and approval from South Korea before taking any options regarding North Korea, Moon also said.
The United States has said it prefers global diplomatic action to stop North Korea's ballistic missile and nuclear programs but it is ready to use force if needed.
However, chief White House strategist Steve Bannon said there was "no military solution" to North Korea's nuclear threats because of the North's massed artillery targeting the South Korean capital.
"Until somebody solves the part of the equation that shows me that 10 million people in Seoul don't die in the first 30 minutes from conventional weapons, I don't know what you're talking about, there's no military solution here, they got us," Bannon told The American Prospect.
Bannon said he was pushing the U.S. administration to take a harder line on China trade and not put complaints against its trade practices in the back seat in the hope it would help restrain the North's leader, Kim Jong Un.
"To me, the economic war with China is everything. And we have to be maniacally focused on that," The American Prospect quoted Bannon as saying.
North Korean media reported on Tuesday that Kim had delayed the decision on firing four missiles towards Guam, a U.S. territory home to an air base and Navy facility, while he waited to see what the United States did next.
"Kim Jong Un of North Korea made a very wise and well reasoned decision," Trump wrote on Twitter on Wednesday. "The alternative would have been both catastrophic and unacceptable!"