The United States and Japan believe UN sanctions against North Korea over its recent nuclear test are having a "great impact" on the regime, officials said on Tuesday after talks between the allies.
Philip Goldberg, the US diplomat tasked with enforcing the United Nations sanctions, met with Akitaka Saiki, Japan's chief negotiator in multilateral talks aimed at persuading North Korea to abandon its nuclear programme.
Goldberg earlier visited South Asian countries and South Korea to study how they have been implementing the UN sanctions, which include an arms embargo and inspections of some North Korean air, sea and land shipments.
"We evaluate that the UN Security Council sanctions, which have been implemented strictly by the international community, are having a significantly great impact on North Korea," Saiki told reporters after the meeting attended by US and Japanese finance, intelligence and defence officials.
Officials did not detail the effects of the sanctions on the regime.
Pyongyang quit the six-party talks aimed at ending its nuclear weapons programme after the UN Security Council censured it for a long-range rocket launch in April. In May the regime staged its second nuclear test.
The United States has urged North Korea to return to the stalled six-party talks, which comprise the two Koreas, the US, China, Japan and Russia.
North Korea has recently made overtures to the United States and South Korea, releasing two jailed US journalists and a South Korean detainee.
It also sent a high-level delegation to former South Korean president Kim Dae-Jung's funeral last weekend and has said it is willing to restart lucrative tourist trips and family reunions for South Koreans.
But Saiki said the United States and Japan, along with South Korea, "would not mix up North Korea's recent phenomenal behaviour with its nuclear problem".
He stressed that Pyongyang should "take actions" and abandon nuclear arms.