WASHINGTON (Reuters) - The United States and Japan will step up their defense cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

U.S. Defense Secretary James Mattis, with his Japanese counterparts, participates in a news conference after their U.S.-Japan Security talks at the State Department in Washington, U.S., August 17, 2017. REUTERS/Jonathan Ernst

“For this threat of North Korea, at this meeting we agreed to increase the pressure and to strengthen the alliance capability,” Japanese Defense Minister Itsunori Onodera said after talks with senior U.S. officials in Washington.

U.S. fears about North Korea’s missile and nuclear bomb programs have grown in recent weeks. Pyongyang has said it was considering plans to fire missiles toward the U.S. Pacific territory of Guam, although North Korean leader Kim Jong Un appears to have delayed the decision.

U.S. Defense Secretary Jim Mattis, Secretary of State Rex Tillerson and their Japanese counterparts agreed at a meeting inWashington on Thursday to work more closely on North Korea.

“In light of the threat of North Korea, the four of us confirmed the importance of the unwavering U.S. commitment to extended deterrence,” Onodera said.

Tillerson said the United States wanted dialogue with Pyongyang, but only if it were meaningful.

“Our effort is to cause them to want to engage in talks but engage in talks with an understanding that these talks will lead to a different conclusion than talks of the past,” he said.

In 2005, North Korea reached an agreement with six countries to suspend its nuclear program in return for diplomatic rewards and energy assistance but the deal later collapsed.

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 toward Guam.

Both sides have since dialed back the rhetoric somewhat.

Trump has vowed not to allow North Korea to develop nuclear missiles that could hit the mainland United States but Pyongyang sees its nuclear arsenal as protection against the United States and its partners in Asia.

Pyongyang’s deputy U.N. ambassador told United Nations Secretary-General Antonio Guterres this week that its nuclear weapons program will never be up for negotiation as long as the U.S. government’s “hostile policy and nuclear threat continue.”

Guterres spoke by telephone with Deputy Ambassador Kim InRyong on Tuesday, the North Korean mission to the United Nations said in a statement on Thursday.

JAPAN WORRIED

Japan intends to expand its role in its alliance with Washington “and augment its defense capabilities” while the United States “remains committed to deploying its most advanced capabilities to Japan,” the State Department said in a statement.

The Japanese Defense Ministry wants to introduce a land-based Aegis missile defense system to address North Korea’s missile threats and has decided to seek funding in the next fiscal year to cover the system design costs, a Japanese defense official told Reuters.

Foreign Minister Taro Kono said Japan would strengthen its defense posture in response to the North Korean threat and provide $500 million to help boost maritime security in East Asia, where China has been pursuing extensive maritime claims.

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Japan is likely to increase its defense spending at a faster pace in its next five-year plan from April 2019 than the annual 0.8 percent average rise in its current mid-term plan, the Nikkei business daily reported on Friday. Defense officials have said such a rise was desirable but finance ministry officials are cautious because of Tokyo’s mammoth public debt.

North Korea has repeatedly threatened to target Japan, which hosts around 54,000 U.S. military personnel, as well as South Korea and the United States with its missiles.

North Korean missiles would have to fly over Japan to reach the Guam area, worrying Tokyo that warheads or missile debris could fall on its territory.

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.

The 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.

The annual exercises have taken on greater significance this year due to the rise in tensions around North Korea’s rapid progress in developing nuclear weapons and missiles capable of reaching the U.S. mainland.

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”. The drill, known as Ulchi-Freedom Guardian, takes place in South Korea. Much of it involves computer-based simulations.

Dunford said the U.S. military and its allies needed to stay ready.

“As long as the threat in North Korea exists, we need to maintain a high state of readiness to respond to that threat,” Dunford told reporters in Beijing after meeting his Chinese counterparts.

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 Defence Ministry cited Fan as saying.

North Korea has in the past fired missiles and taken other steps in response to U.S. and South Korean exercises.

Easing tensions this week, North Korean media announced that Kim delayed a decision on firing four missiles toward Guam, home to a U.S. air base and Navy facility. Trump welcomed the delay as “very wise.”