US President Donald Trump said Friday the United States stands behind Japan "100 percent" in a previously unscheduled joint news conference he held with Japan's prime minister after North Korea conducted a surprise ballistic missile launch.

Japanese Prime Minister Shinzo Abe opened the brief news conference at Trump's Mar-a-Lago resort in Florida, denouncing the North's missile launch as "absolutely intolerable" and urging the communist nation to comply with all UN Security Council resolutions.

"During the summit that I had with President Trump, he assured me that the United States will (be) always with Japan 100 percent and to demonstrate his determination as well as commitment, he is now here with me at this joint press conference," Abe said during the conference.

Abe said he and Trump agreed to promote further collaboration and reinforce the alliance.

Trump then stepped forward and said, "I just want everybody to understand and fully know that the United States of America stands behind Japan, its great ally, 100 percent."

The North's missile launch, which took place on Sunday morning (local time), came after North Korean leader Kim Jong-un threatened last month to test-fire an intercontinental ballistic missile apparently capable of striking the US Officials at South Korea's Joint Chiefs of Staff said that the North's missile, which flew about 500 kilometers, appears to be either an intermediate-range Musudan or the medium-range Nodong missile, not an intercontinental ballistic missile.

The US Strategic Command also confirmed the North's launch, saying it detected and tracked what appears to be either a medium- or intermediate-range ballistic missile, and the missile posed no threats to North America.

Trump and Abe held a summit at the White House on Friday.

After the talks, Trump said the two sides agreed to work closely together to cope with the nuclear and missile threats from the North. He also said defending against the North's threats is a "very very high priority."

The two sides also issued a joint statement strongly urging the North to abandon its nuclear and ballistic missile programs, and not to take any further provocative actions. They also reaffirmed their commitment to fully implement U.N. sanctions on Pyongyang. (Yonhap)