SINGAPORE (Reuters) - U.S. Defense Secretary Robert Gates warned on Saturday that the United States would not accept a nuclear North Korea and the growing threat could trigger an arms race in Asia.

In a speech to an Asian defense conference in Singapore, Gates also warned Pyongyang against transferring nuclear technology abroad.

“We will not stand idly by as North Korea builds the capability to wreak destruction on any target in the region or on us,” Gates told a meeting on defense ministers in Singapore.

“We will not accept North Korea as a nuclear state.”

Gates said the Obama administration would hold North Korea “fully accountable” if it transferred any nuclear material outside its borders.

“The transfer of nuclear weapons or material by North Korea to states or non-state entities would be considered a grave threat to the United States and our allies. And we would hold North Korea fully accountable for the consequences of such action.”

The statement seemed to harden and broaden the Obama administration’s stand on North Korea’s recent series of provocations from a regional security issue to a global proliferation threat.

This week North Korea has detonated a nuclear device, launched a series of missiles, including one on Friday, and threatened to attack South Korea.

Gates’ speech will reassure allies such as Japan and South Korea that the new Obama administration will stand firm on the Cold War’s last frontier on the Korean peninsula.

His remarks may also be intended to send a message to would-be buyers of North Korean missile and nuclear technology. Impoverished North Korea earns an estimated $1.5 billion a year from missile sales, and past customers include Pakistan, Libya, Iran, Syria and Egypt.

But Gates said the U.S. did not view North Korea as a direct military threat now and Washington’s next step would be political in reaching out to other regional powers.

He was due to meet Japan and South Korea’s defense ministers later on Saturday for a trilateral discussion about North Korea and regional security issues.

A South Korean newspaper reported on Saturday that North Korea is preparing to move an intercontinental ballistic missile from a factory near Pyongyang to a launch site on the east coast.

North Korea has warned of an intercontinental ballistic missile test in anger over U.N. Security Council punishment of what Pyongyang said was a satellite launch on April 5.

Gates said North Korea is creating an environment in the region that may spark an Asian arms race.

“If they continue on a path they are on, I think the consequences for stability in the region are significant and I think it poses the potential, the potential for some kind of an arms race in this region.”

He said strong financial sanctions were needed to tackle North Korea, echoing comments made by Australia’s Prime Minister Kevin Rudd at the defense meeting on Friday.

Rudd, in a keynote address to the defense conference, said North Korea only responds to a unified stand from the international community.

“The first test of strength will be what measures we embrace as an international community through the U.N. Security Council,” he said. “The measures have to be uniform and strong.”