The US Department of Defense said Tuesday that there are "plenty" of images of the White House and the Pentagon already available online, after North Korea claimed its military spy satellite took photos of key US government and military facilities.

In a press briefing, Brig. Gen. Patrick Ryder, the department's press secretary, also reiterated the United States' "ironclad" defense commitment to South Korea, as Pyongyang started reinstalling guard posts and heavy weapons along the Demilitarized Zone separating the two Koreas.

"I will say that there are plenty of images of the Pentagon and the White House online," Ryder said. "So, let's leave it at that."

On Tuesday, the North claimed that its satellite took photos of the White House, the Pentagon, Norfolk Naval Station, Newport News Shipyard and a Virginia airfield -- in an apparent message signaling that it has started employing the satellite to monitor key US sites.

But skepticism has emerged over whether the quality of those photos would be sufficient enough to aid military operations given that it might not have been able to acquire a high-resolution camera for satellite reconnaissance activities.

The North launched the satellite, Malligyong-1, on a Chollima-1 rocket on Nov. 21 after two failed attempts in May and August, respectively.

Asked to comment on what constitutes a success of the North's launch, Ryder pointed out that the US is aware that it went into orbit.

"We know that it went into orbit. For something to go into orbit, it needs to escape Earth's gravity and be able to be sustained in orbit around the Earth," he said. "So really, it would be up to the North Koreans to define what the parameters of this launch were and what they were hoping to achieve."

He added that the US will stay in close consultation with South Korea, Japan and other partners and monitor related developments closely.

On the North's recent activities along the DMZ, Ryder highlighted America's security commitment to South Korea and Japan.

"What I will say is that the US' extended deterrence to both the Republic of Korea (ROK) and Japan will remain ironclad," he said, referring to America's commitment to using the full range of its military capabilities, including nuclear, to defend its allies.

"As you know, Secretary Austin just returned from his second trip this year to the Korean Peninsula and he was very clear (that) after seven decades of preserving peace and stability on the Korean Peninsula, the US-ROK alliance stands strong," he said.

After it said it would not be bound by a 2018 inter-Korean military tension reduction deal last week, the North began restoring measures suspended under the deal.

The deal called for demolishing border guard posts within 1 kilometer of the border, banning military drills and maneuvers near land and sea borders, and establishing no-fly zones along the border, among other measures aimed at reducing cross-border tensions and accidental clashes. (Yonhap)