U.S. Secretary of State Condoleezza Rice has urged North Korea to make a complete and accurate declaration of all its nuclear programs.

In a news conference on Friday, she declined to comment the Washington Post report that traces of uranium were found on aluminum tube parts obtained from North Korea.

She pointed out that the United States had long been concerned that the North’s highly enriched uranium program could serve as an alternative route to build nuclear weapons.

Rice said she sincerely hoped North Korea would make the declaration by year’s end but emphasized getting the process right.

When asked about the possibility of a visit to North Korea, Iran and Syria, she did not rule it out, saying the U.S. doesn’t have “permanent enemies.”