The White House warned North Korea that any attack on American allies or territory could result in a nuclear weapon being used on the country.
President Trump spoke with Japanese Prime minister Shinzo Abe for the second time this weekend on Sunday and told him the United States would back Japan up in case of any attack from North Korea.
The statement came after Trump sent Defense Secretary Jim Mattis to tell reporters Trump had been briefed on all options to respond to North Korea's sixth nuclear test, said to be a hydrogen bomb.
Mattis said the United States has the ability to "annihilate" North Korea, but doesn't want to and will continue to use diplomatic means to de-escalate the situation.
However, the White House made it clear that any attack on American territory or her allies would bring a strong military response — and explicitly mentioned nuclear weapons.
"President Trump reaffirmed the commitment of the United States to defending our homeland, territories, and allies using the full range of diplomatic, conventional, and nuclear capabilities at our disposal," the statement read.
The White House said North Korea's test of a nuclear weapon would not drive the allies apart.
"The two leaders condemned North Korea's continued destabilizing and provocative actions, confirmed the two countries' ironclad mutual defense commitments, and pledged to continue close cooperation," the statement read.