North Korea is unlikely to be taken off the U.S. terrorism blacklist within the 45-day process set in motion by President George W. Bush in June. The process ends Monday.

Sources in Washington said Sunday that the delay is due to Pyongyang's failure to submit a detailed plan to verify its nuclear declaration.

U.S. State Department acting deputy spokesman Gonzalo Gallegos said the U.S. must see a "strong verification regime" before removing the communist state from the list. He said Washington will assess the North's verification efforts at the end of the 45-day period Monday

National Security Council senior director Dennis Wilder said that unless the North delivers a robust verification before Monday, it will remain on the blacklist.