Reports from South Korea and Japan indicate North Korea has tested what could be its largest intercontinental ballistic missile (ICBM) yet. While North Korea has held several launches in recent months, Thursday’s launch was the first to test a North Korean ICBM since 2017, when three test flights demonstrated the potential range to reach the American homeland. The United States had already indicated last month North Korea was preparing for a launch of a new large ICBM first unveiled in October 2020.

“This launch is a brazen violation of multiple UN Security Council resolutions and needlessly raises tensions and risks destabilizing the security situation in the region,” White House Press Secretary Jen Psaki said in a White House statement condemning Thursday’s launch. “This action demonstrates that the DPRK continues to prioritize its weapons of mass destruction and ballistic missile programs over the well-being of its people.”

According to South Korea’s Joint Chiefs of Staff, North Korea’s intercontinental missile traveled 670 miles and reached a maximum altitude of over 3,850 miles. Japan’s Deputy Defense Minister Makoto Oniki said the flight details suggested a new type of ICBM. Kim Dong-yub, a professor at Seoul’s University of North Korean Studies, said flight details suggest the missile could reach targets 9,320 miles away when fired on normal trajectory with a warhead weighing less than a ton. That would place the entire U.S. mainland within striking distance.

“North Korea’s intercontinental ballistic missile launch today is a serious challenge and an act of threat against the Korean people’s desire, the international community’s demands and related countries’ efforts for the denuclearization and peace of the Korean Peninsula,” First Deputy Director of South Korean National Security Office Suh Choo-suk. Japanese Prime Minister Fumio Kishida described the missile launch as “an unforgivable recklessness.”

Denuclearization talks with the U.S. have been stalled since 2019, after the Americans rejected North Korea’s demand for major sanctions relief in exchange for a partial surrender of its nuclear capabilities. Prime Minister Kishida and President Joe Biden discussed North Korea’s intercontinental ballistic missile launch on the sidelines of the G-7 summit Thursday. According to the White House, the two stressed the need for diplomacy and agreed to continue working together to hold Pyongyang responsible.

“We urge all countries to hold the DPRK accountable for such violations and call on the DPRK to come to the table for serious negotiations,” Psaki said. “The door has not closed on diplomacy, but Pyongyang must immediately cease its destabilizing actions.”