On Friday, the highest ranking U.S. general reiterated the United States’ “ironclad commitment” to the safety and security of its strategic ally, Japan, following escalated tension on the Korean Peninsula over North Korea’s nuclear activities. The general told his Tokyo counterpart that a threat or an attack on one side would be considered a threat or an attack on both sides.

North Korea’s nuclear weapons program

In recent weeks, fears about Pyongyang’s nuclear weapons program have intensified. Last week, Pyongyang announced it was studying plans to launch four missiles off the coast of Japan towards the tiny Pacific island of Guam which is a U.S.

territory. Days later, North Korean leader Kim Jong Un delayed the decision to carry out the strike.

On Thursday, U.S. Defense Secretary Jim Mattis and his Secretary of State counterpart Rex Tillerson at a meeting in Washington with the Japanese Foreign Affairs Minister pledge to work together on North Korea.

The U.S. Secretary of State said Washington is ready to dialogue with Pyongyang only if it is meaningful. Tillerson added that the U.S. effort is to persuade North Korea to see the need for dialogue with an understanding that these negotiations will give rise to a different conclusion.

In 2005, a six-party conference involving the U.S., China, South Korea, Japan, Germany and North Korea reached an agreement.

The deal mandated Pyongyang to suspend its missile and nuclear weapons program in exchange for energy aid and diplomatic rewards, but the pact later collapsed. Tensions have heightened amid North Korea’s launch of two intercontinental ballistic missiles (ICBM) in July, which attracted widespread condemnation from world leaders and attracted a wider United Nations Security Council sanctions against Pyongyang.

U.S. President Donald Trump vowed to take all necessary steps to prevent North Korea from acquiring nuclear weapons capable of hitting the U.S. mainland. However, Pyongyang views it as protection against aggression by Washington and its allies.

Joint military exercises

On Thursday, Dunford said the U.S. and South Korea would move forward with the joint military exercises billed to commence next week despite mounting pressure from Pyongyang and its main ally, China to cancel the drills that North Korea routinely describes as rehearsals for war.

Last week, Trump issued series of warning to North Korea that it would be confronted with “fire and fury” if it threatens the United States, and that the U.S. military is “locked and loads” if Pyongyang acts unwisely.