PYONGYANG, North Korea – Hinting at a missile launch, North Korea delivered a fresh round of war rhetoric Thursday with claims it has “powerful striking means” on standby.

Seoul and Washington speculated that the North is preparing to test-fire a missile designed to be capable of reaching the U.S. territory of Guam in the Pacific Ocean.

The latest rhetoric came as new U.S. intelligence was revealed showing North Korea is now probably capable of arming a ballistic missile with a nuclear warhead.

On the streets of Pyongyang, North Koreans shifted into party mode as they celebrated the anniversary of leader Kim Jong Un’s appointment to the country’s top party post — one in a slew of titles collected a year ago in the months after the death of his father, Kim Jong Il.

But while there was calm in Pyongyang, there was condemnation in London, where foreign ministers from the Group of Eight nations slammed North Korea for “aggressive rhetoric” that they warned would only further isolate the impoverished, tightly controlled nation.

North Korea’s provocations, including a long-range rocket launch in December and an underground nuclear test in February, “seriously undermine regional stability, jeopardize the prospects for lasting peace on the Korean Peninsula and threaten international peace and security,” the ministers said in a statement.

In the capital of neighboring South Korea, the country’s point person on relations with the North, Unification Minister Ryoo Kihl-jae, urged Pyongyang to engage in dialogue and reverse its decision to pull workers from a joint industrial park just north of their shared border, a move that has brought factories there to a standstill.

“We strongly urge North Korea not to exacerbate the crisis on the Korean Peninsula,” Ryoo said.

North Korea probably has advanced its nuclear knowhow to the point where it could arm a ballistic missile with a nuclear warhead, but the weapon wouldn’t be very reliable, the U.S. Defense Intelligence Agency has concluded. The DIA assessment was revealed Thursday at a public hearing in Washington.

President Obama warned the unpredictable communist regime that his administration would “take all necessary steps” to protect American citizens.

In his first public comments since North Korea escalated its rhetoric, Obama urged the North to end its nuclear threats, saying it was time for the isolated nation “to end the belligerent approach they have taken and to try to lower temperatures.”

U.S. Secretary of State John Kerry was headed to Seoul on Friday for talks with South Korean officials before heading on to China.

“If anyone has real leverage over the North Koreans, it is China,” U.S. Director of National Intelligence James Clapper told Congress on Thursday. “And the indications that we have are that China is itself rather frustrated with the behavior and the belligerent rhetoric of … Kim Jong Un.”

In the latest threat from Pyongyang, the Committee for the Peaceful Reunification of the Fatherland, a nonmilitary agency that deals with relations with South Korea, said “striking means” have been “put on standby for a launch and the coordinates of targets put into the warheads.” It didn’t clarify, but the language suggested a missile.