The United States on Thursday condemned North Korea's ballistic missile launches as "destabilizing" actions violating multiple UN Security Council resolutions.

"The United States condemns the DPRK's destabilizing ballistic missile launches. These launches violate multiple UN Security Council resolutions and threaten the region and the broader international community," a department spokesperson told Yonhap News Agency in an email.

"Our commitment to the defense of the Republic of Korea and Japan remains ironclad. North Korea's unlawful nuclear and ballistic missile programs constitute serious threats to international peace and security and undermine the global nonproliferation regime," the official added.

Earlier reports said the United Nations will convene a meeting of its North Korea sanctions committee Friday.

South Korea said the North fired what appeared to be two short-range ballistic missiles into the East Sea on Thursday.

On Friday (Seoul time), the North said it has successfully launched a newly developed tactical guided projectile.

US President Joe Biden warned his country and its allies will respond should the North continue to escalate tensions.

"We are consulting with our allies and partners, and there will be responses if they choose to escalate. We will respond accordingly," he said in a press conference earlier Thursday, also noting the latest missile launches violated at least one UN Security Council resolution.

The North is prohibited from testing any type or range of ballistic missiles under UN resolutions.

Pyongyang also launched two cruise missiles Sunday.

Biden had then said "nothing much has changed," after US officials noted cruise missiles are not covered or prohibited by UN Security Council resolutions. (Yonhap)