North Korea on Friday confirmed it had tested a new guided missile, as President Joe Biden warned of consequences if Pyongyang escalates tensions amid stalled nuclear negotiations.

The North’s official Korean Central News Agency said the two “new-type tactical guided projectiles” accurately hit the target off the eastern coast on Thursday. Photos on the website of the North’s main Rodong Sinmun newspaper showed a missile lifting off from a transport erector launcher amid bright flames.

KCNA quoted top official Ri Pyong Chol, who supervised the test, as saying that the new weapon’s development “is of great significance in bolstering up the military power of the country and deterring all sorts of military threats existing on the Korean Peninsula.”

Japanese officials said both weapons tested Thursday were ballistic missiles, which are prohibited by U.N. Security Council resolutions. According to South Korean officials, North Korea fired two other missiles on Sunday but they were likely cruise missiles, which are not banned.

The test-firings were the North’s first major provocation since Biden took office in January. Some experts say North Korea aimed to apply pressure on the Biden administration to boost its leverage in future talks.

“We’re consulting with our allies and partners,” Biden told a news conference Thursday. “And there will be responses if they choose to escalate. We will respond accordingly. But I’m also prepared for some form of diplomacy, but it has to be conditioned upon the end result of denuclearization.”

The United States has asked for a meeting of the U.N. Security Council committee that monitors sanctions against North Korea, and it’s set to take place Friday morning behind closed doors. The committee includes representatives from all 15 nations on the council.

South Korean President Moon Jae-in, who’s pursuing better ties with North Korea, issued a rare criticism of Pyongyang on Friday over the launches.

“I know very well our people have big worries about North Korea’s missile launches yesterday,” Moon said during a military ceremony. “Now is time for South and North Korea and the United States to make efforts to (resume) talks. An act that hampers the dialogue mood is not desirable at all.”

U.S.-North Korea talks on curbing the North’s nuclear ambitions have been in a limbo for about two years due to disputes over U.S.-led sanctions on the North. In January, North Korean leader Kim Jong Un said he would expand his weapons arsenal and build up his country’s military capability to cope with what he called American hostility.

KCNA said the new weapon’s warhead weight has been improved to 2.5 tons (5,510 pounds). It said Thursday’s test also confirmed the reliability of the improved version of the weapon’s solid fuel engine, which would boost missile mobility, and of its low-altitude, maneuverable flight.

South Korean observers said the weapon is likely an upgraded North Korean version of the Russian-made Iskander, a short-range nuclear-capable missile designed to fly at a low altitude and make in-flight guidance adjustments. They said it has a better chance of evading missile defense systems in South Korea.

Japanese Defense Minister Nobuo Kishi said Friday the North Korean weapon is a new type of ballistic missile that was shown during a military parade in Pyongyang in January. Kishi said Japan would strengthen its missile defense system to “ensure peace and safety.”