The United States on Friday vowed to keep up its tough sanctions regime on North Korea after Pyongyang said it had reached the final stage of enriching uranium.
"We continue to be committed to ensuring that North Korea upholds its international obligations and we continue to strongly implement the sanctions that were approved," White House spokesman Robert Gibbs said.
"Our goal continues to be, and will continue to be the denuclearization" of the Korean peninsula, he said.
In a defiant response to tougher UN sanctions, North Korea said Friday it was building more plutonium-based atomic weapons and was near completing an experimental uranium enrichment effort.
"Experimental uranium enrichment has successfully been conducted to enter into completion phase," the official Korean Central News Agency quoted its permanent representative to the United Nations as saying.
"Reprocessing of spent fuel rods is at its final phase and extracted plutonium is being weaponized," the representative said in a letter to the UN Security Council president.
The North had recently struck a more conciliatory note after months of tension, but said Friday it was prepared "for both dialogue and sanctions."
Pyongyang for years denied US allegations of a secret enriched uranium bomb-making program, in addition to the admitted plutonium-based operation which fueled two nuclear tests.
But on June 13, a day after the UN punished Pyongyang's latest test with tighter sanctions, the North vowed to start an enriched uranium program and to extract more plutonium from spent fuel rods at its Yongbyon reactor.
