South Korean President Moon Jae-in said that any military action against Kim Jong Un’s regime requires his nation’s approval, and vowed to prevent war at all costs.

“There will be no war repeated on the Korean Peninsula,” Moon said in a speech on Tuesday marking the anniversary of the end of Japanese occupation in the 1940s. Military action against North Korea should be decided by “ourselves and not by anyone else,” he said.

While Moon said that South Korea would work with the U.S. to counter security threats, he emphasized the need to focus on diplomatic efforts. Sanctions were designed to bring North Korea to the negotiating table over its nuclear and missile weapons programs, he said.

The comments from a key U.S. ally contrast with the threats of war coming from President Donald Trump, who vowed to unleash “fire and fury” on Pyongyang if Kim persists with advancements in his arsenal, particularly intercontinental ballistic missiles. Trump’s rhetoric has raised concerns that a miscalculation — or unilateral action by the U.S. — could spark a military conflict that risks devastating North Korea’s neighbors.

The diminishing prospects of war have helped equities to rally. Stock indexes from Tokyo to Hong Kong to Sydney climbed on Tuesday after the S&P 500 Index surged 1 percent, while havens such as gold, Treasuries and the yen retreated.

‘Game On’

Defense Secretary Jim Mattis warned on Monday that it would be “game on” for war if North Korea fired missiles that hit the U.S. or its territories, including the Pacific island of Guam.

“It could escalate into war very quickly — yes, that’s called war,” Mattis told reporter at the Pentagon. “If they shoot at the United States, I’m assuming they hit the United States — if they do that, then it’s ‘game on’.” Asked if he considers Guam part of the U.S., he said, “Yeah, it sure is.”

Kim discussed plans to fire four intermediate-range ballistic missiles over Japan into waters near Guam with his commanding officers during an inspection of military forces on Monday, the state-run Korean Central News Agency reported. The North Korean leader said he will watch the U.S.’s conduct “a little more” and praised his strategic force for drawing up “a close and careful plan,” KCNA said.

North Korea first fired a missile over Japan in 1998, prompting the Japanese government to initiate its current ballistic missile-defense system with the U.S. While a second attempt failed in 2005, North Korea again succeeded in launching one in 2009 that flew over northern Japan and continued for another 3,000 kilometers before landing in the Pacific.

Unprecedented Tensions

Japanese Prime Minister Shinzo Abe spoke with Trump by phone on Tuesday and agreed on the need to prevent North Korea from launching missiles. Pyongyang is raising tensions to unprecedented levels, Abe told reporters in Tokyo.

“In this situation, we are highly appreciative of President Trump’s commitment to the safety of U.S. allies,” Abe said. He said it’s important to work with South Korea and countries like China and Russia to stop the threat from North Korea.

Moon took power in May promising more engagement with North Korea following almost a decade of conservative rule. Last month, he said that under the right circumstances he’s willing to meet Kim "anytime, anywhere."

The U.S. has almost 30,000 military personnel stationed in South Korea and has assured the country’s security since the Korean War ended without a peace treaty almost six decades ago. South Korea is positioned to suffer the most from any hostilities with North Korea, with Seoul’s 10 million residents in range of North Korea’s artillery and rockets.

Dr. Strangelove

One of Moon’s advisers earlier this week criticized Trump’s rhetoric against North Korea, calling it “very unusual.” The president’s comments have raised concerns that the U.S. might be willing to accept collateral damage among its Asian allies to protect the American homeland.

South Carolina Senator Lindsey Graham, a Republican, told NBC News that Trump told him that “if thousands die, they’re going to die over there.” Joseph Dunford, chairman of the U.S. Joint Chiefs of Staff, said last month that it was “unimaginable” to allow North Korea to develop the capability to strike a U.S. city with a nuclear weapon.

On a trip to Seoul this week, Dunford told Moon that the Trump administration is putting a priority on diplomatic and economic pressure.

Mattis echoed those comments on Monday, cautioning against portraying his words as a virtual declaration of war.

“It’s not that I’m over here — Dr. Strangelove,” he said, but “you don’t shoot at people in this world unless you want to bear the consequences.”

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