Washington, Jul 3 (IANS): A Pentagon spokesperson criticised North Korea's recent ballistic missile launches as "irresponsible," and reiterated the US' calls for the recalcitrant regime to return to diplomacy.

Pentagon Press Secretary Maj. Gen. Pat Ryder made the remarks after Pyongyang claimed to have conducted a multiple warhead missile capability test last week, and test-fired a new tactical ballistic missile capable of carrying a super-large warhead this week, Yonhap news agency reported.

"Again, we continue to highlight the fact that this kind of destabilising, disruptive behavior is irresponsible. We continue to call on North Korea to return to diplomatic discussions," Ryder told a press briefing.

"But in those particular launches, while there was no assessment that it posed a threat to the US or our allies or partners in the region, it is something that we will continue to take seriously," he added.

The North's stated pursuit of multiple warhead technology has been a new source of security concern as the technology, if acquired, would enable the regime to strike multiple targets with a single missile.

Commenting on the North Atlantic Treaty Organization (NATO) summit slated to take place from July 9-11 in Washington, Ryder said that the transatlantic alliance's partnership with South Korea and other regional partners would be an agenda item.

"During the summit, Secretary Austin will be engaged in discussions to ramp up transatlantic defence industrial production, ensure adequate defence investments from allies and the deepening of practical cooperation between NATO and its Indo-Pacific partners to include Australia, Japan, New Zealand and the Republic of Korea," he said, referring to South Korea by its official name.

He further said, "Since its creation 75 years ago, NATO has been the greatest defensive alliance in human history. Next week's summit underscores the US' unwavering commitment to NATO and the alliance's critical role in maintaining global security and stability."