Japan will continue the economic sanctions it leveled against North Korea despite Pyongyang's apparent about-face on returning to the multilateral talks to end its nuclear threat, Chief Cabinet Secretary Yasuhisa Shiozaki told a news conference Wednesday.

The top government spokesman pointed out it is still not clear if the North will end its nuclear weapons program as demanded in a recent U.N. Security Council resolution and a joint declaration from the six-party talks in September 2005.

"We will calmly implement what we decided to do as long as it remains unclear if (North Korea) will abide by" those requests, Shizoaki said.