Speaking Friday at the Foreign Press Center in Washington to mark the first anniversary of U.S. President Barack Obama's inauguration, Mike Hammer, spokesman for the National Security Council, said Pyongyang must return to the suspended six-party talks before removal of sanctions can be considered, the South Korean news agency Yonhap reported.
"Our focus with our partners in the six-party talks is denuclearization of the Korean Peninsula and, once that happens, we can start looking at other things," Hammer said.
North Korea has said it wants the United Nations to remove sanctions imposed after last year's missile test before it comes back to the table, and is also looking for the imposition of a permanent peace treaty to settle the 1950-53 Korean War.
"We don't know yet if they are ready to go down that path (to denuclearization talks)," Yonhap quoted Hammer as saying. "They sometimes say things that are encouraging and then only to say other things that seem to indicate that they're not prepared to do so."