WASHINGTON (Yonhap) -- The U.S. government indicated Thursday that it has not detected any clear signs that North Korea's nuclear test is around the corner.

"Nothing to point to, I mean, other than the rumors that we've heard in the press and elsewhere," Mark Toner, deputy spokesman for the State Department said at a press briefing.

He was responding to media reports that Pyongyang seems to be all set for a third nuclear experiment. It conducted underground nuclear tests in 2006 and 2009.

Toner stressed that North Korean leadership should make a choice between dialogue and isolation.

"North Korea has a clear choice in front of it," he said. "And if it continues its bad behavior, it's just only going to further isolate itself."
Citing unidentified sources, some media reported that the North may detonate a nuclear device as early as this week.

Toner added he "can't speak to any intelligence" that the U.S. might have on the issue.

He also refused to go into details on another sensitive topic _ South Korea's push to bolster its ballistic missile capabilities.

The South's President Lee Myung-bak openly declared a need to develop longer-range ballistic missiles to counter the North's threats.