1.   But North Korea refused to accept reactors supplied by South Korea, its archenemy, contending that its models are unsafe.

2.   North Korea threatened on Wednesday to scrap its four-month-old agreement with the United States if Washington tried to force it to accept South Korean reactors.

3.   At a news conference, the U.S. negotiator said North Korea still had not agreed to accept reactors made in South Korea.

4.   But efforts to implement the deal are at an impasse because North Korea refuses to accept replacement reactors from its southern rival.

5.   But efforts to implement the deal have deadlocked after North Korea refused to accept replacement reactors from its southern rival.

6.   But North Korea has balked at accepting reactors made by its southern rival.

7.   But North Korea warned Tuesday it will not accept reactors from its southern rival.

8.   But Pyongyang is refusing to accept South Korean reactors that the United States is offering.

9.   But the North has refused to accept South Korean reactors.

10.   But the North is refusing to accept South Korean reactors that the United States is offering as replacements.