US Defense Secretary Jim Mattis slammed North Korea's actions as 'reckless,' referring to the totalitarian regime's nuclear weapons and missile programs.

His comments came during a Friday news conference with his British counterpart Michael Fallon in London. Asked by a journalist about the threat posed by Iran, the US defense secretary pivoted to North Korea, saying the hard-line regime has "got to be stopped."

North Korea is believed to be preparing for a new nuclear test, and Mattis called the threat posed by Pyongyang increasingly urgent. This prompted a reporter to point out that when Mattis was the head of US Central Command in 2012, he said Iran was the most worrying threat facing the US.

"In the larger scheme of things," Mattis said, North Korea is now the more urgent threat.

"This is a threat of both rhetoric and growing capability," Mattis said, adding that the North Koreans are acting "in a very reckless manner" and that the US had to act accordingly.

Defending past comments

Iran remains a threat, as well, continuing to behave as an exporter of terrorism and a sponsor of militant activity, Mattis said, defending his comments from five years ago.

"At the time when I spoke about Iran I was a commander of US Central Command and that (Iran) was the primary exporter of terrorism, frankly, it was the primary state sponsor of terrorism and it continues that kind of behavior today," Mattis said.

The defense secretary also expressed growing concern about Russia's presence in Afghanistan and its connections to the Taliban.

"We have seen Russian activity vis-à-vis the Taliban," Mattis said.

"I'm not going to say at this point if that has manifested into weapons and that sort of thing, but certainly what they're up to there in light of their other activities gives us concern."

Mattis said he had not yet decided whether to recommend an increase in US troop numbers in Afghanistan.

The US first invaded Afghanistan in 2001, shortly after the September 11 terror attack on the US. The military attack succeeded in ousting the Taliban, who had given safe haven to Osama bin Laden, the mastermind behind the attack on the US. But the Islamic militants continue to reconstitute, and threaten the Afghan government's fragile hold on power.

Former President Barack Obama technically ended the war in Afghanistan in 2014 by withdrawing virtually all US combat troops from the country. But the US has maintained a limited military presence, primarily in an advisory capacity.

bik/es (AP, Reuters)