The Biden administration reached out to allies in the region on diplomatic and military fronts after North Korea launched a long-range missile.
The missile flew over Japan before landing in the ocean.
The last time a North Korean missile was fired directly over Japan was five years ago. People in northern prefectures were told to take shelter.
The White House said in a statement that Biden spoke to the Japanese Prime Minister to reinforce America's "ironclad commitment to Japan's defense."
The White House said the presidential call followed Monday night conversations between the National Security Adviser and the Secretary of State with their Japanese and South Korean counterparts.
The Pentagon said that Defense Secretary Lloyd Austin spoke with his counterparts in Tokyo and South Korea.
Each of these U.S. officials described America's commitment to the defense of Japan and South Korea using the word "clad."
The military alliances were visible in the skies above northeastern Asia.
On Tuesday, the U.S. and South Korea conducted aerial flight and precision targeting exercises in response to the missile launch. A target was fired at during the exercise.
Jean-Pierre said at the White House that there was a joint exercise between the US and Japan.
John Kirby, a spokesman for the National Security Council, said that the exercises Tuesday were held to strengthen trilateral coordination in the face of a threat that continues to grow.
Kirby said that North Koreans learn from each launch.
He said that they want to stay vigilant and make sure that they have the ability to defend their national interests.