SEOUL (REUTERS) - North Korea launched a "newly developed new-type tactical guided projectile" on Thursday, state news agency KCNA reported on Friday (March 26).

The report suggested North Korean leader Kim Jong Un did not inspect the launch.

The United States condemned North Korea's ballistic missile launches this week and said the country's nuclear and ballistic missile programmes constituted serious threats to international peace and security.

"The United States condemns (North Korea's) destabilising ballistic missile launches," a State Department spokesman said on Thursday. "These launches violate multiple UN Security Council resolutions and threaten the region and the broader international community."

US President Joe Biden said on Thursday the United States remained open to diplomacy with North Korea despite its missile tests this week, but warned there would be responses if North Korea escalates matters.

The new weapon is based on existing technology that was improved to carry a 2.5-ton warhead, KCNA reported.

The pair of test-fired weapons accurately hit a target 600km away, KCNA said.

"The development of this weapon system is of great significance in bolstering up the military power of the country and deterring all sorts of military threats," Ri Pyong Chol, the senior leader who oversaw the test, said, according to KCNA.

Photos released by state media showed a black-and-white painted missile blasting off from a military launch vehicle.