SEOUL, South Korea (AP) — North Korea escalated its renewed confrontation with the U.S. on Friday, saying it is moving to restore a nuclear reactor and warning it "will go its own way" because Washington refuses to remove it from the U.S. terror blacklist.

The announcement was the communist regime's first confirmation it has started undoing the dismantlement of its nuclear program begun last November under an atomic disarmament deal that promised energy aid to the impoverished nation.

Its threat came amid reports that leader Kim Jong Il suffered a stroke, news that has fueled worries about instability in North Korea.

Analysts noted that Pyongyang has a history of taking a hard line in negotiations to press for further concessions. They said the North didn't appear to be seeking to scuttle six-nation talks since its envoys went ahead with a meeting with South Korean diplomats Friday.

Pyongyang blamed Washington for the turnaround, saying the U.S. refusal to remove North Korea from a list of states that sponsor terrorism violated its agreement with the U.S.

State Department spokesman Sean McCormack told reporters in Washington the North has been "getting closer and closer" to the point where it can restart its Yongbyon reactor.