Bilateral talks in Washington on Thursday between Defense Secretary James Mattis, Secretary of State Rex W. Tillerson, Japanese Defense Minister Itsunori Onodera and Foreign Minister Taro Kono, took place days after North Korea backed off threats to test launch missiles against USA military targets in Guam, missiles that would fly over Japanese airspace.
"In the event of a missile launch towards the territory of Japan, Guam, United States, Korea, we would take immediate, specific actions to take it down", he stated.
The war games, details of which are a closely guarded secret, simulate military conflict with the isolated country.
On Wednesday, two Japanese F-15 jet fighters conducted air maneuvers with two U.S. Air Force B-1B Lancer bombers over the southwestern part of the Korean Peninsula. Trump got attention - and sparked alarm - with comments that threats from Kim Jong Un's regime, which has pledged to develop a nuclear missile that could hit the USA mainland, would be met with "fire and fury". "We will cooperate to advance trilateral and multilateral security and defence cooperation with other partners in the region, notably the Republic of Korea, Australia, India and other southeast Asian countries", US Secretary of State Rex Tillerson told reporters at a news conference here with Defence Secretary James Mattis.
North Korea said it is holding fire on Guam but is watching the action of the U.S. before deciding to hit the American territory with missiles.
As the top USA diplomat, Tillerson said Washington would continue diplomatic efforts "first and foremost", but "it is only prudent" that military action remains a choice.
Also Friday, William Hagerty, the new USA ambassador to Japan, said he had arrived at a hard time and that the US wants to work with Japan to "calm the rhetoric" over North Korea. On the threat of ballistic missiles, as an alliance, we will strengthen our defense and capabilities to respond. The US and Japan were taking steps in the face of that threat, he added.
North Korea has repeatedly threatened to target Japan, home to numerous USA military installations.
"We agreed to bolster our alliance capabilities to deter and respond to North Korea's unacceptable behaviour and other challenges to regional security", Tillerson said.
Dunford said on Thursday the United States and South Korea would go ahead with joint military drills next week despite pressure from North Korea and its main ally, China, to halt the contentious exercises that Pyongyang routinely describes as preparation for war. But he dismissed claims that any talks between Pyongyang, the US and its allies could take place before the North agrees to abandon its nuclear ambitions.
Japan and the United States also launched joint live-fire drills on a northern Japanese island last week.
The foreign minister stressed that "it is important to deter North Korea from its continued provocative statements and actions" and called on Russian Federation and China to play a bigger role, including in what concerns the implementation of the United Nations Security Council resolutions. "I read those", Mr Tillerson said.
"For the current system, with the SM-3 IB missile, the answer is no, it does not have any capability for use against ICBMs headed to the U.S. The next generation of missiles, now under co-development by the U.S. and Japan, is faster and would have more capability against faster missiles". The Japanese-administered Senkaku Islands are also claimed by China and Taiwan.
Tillerson warned that the United States will honor treaty obligations to defend Japan "without reservation", and would be working to improve military alliances with other countries in the region, including South Korea, India and Australia.