North Korea is showing no signs of preparing to conduct a nuclear test, despite its threat to do so in anger over a U.N. General Assembly resolution on its human rights violations, a U.S. think tank said Wednesday.

The website 38 North made the assessment, saying commercial satellite imagery shows that there has been "low-level activity" at the North's Punggye-ri underground nuclear test site for the past four months.

"It is unlikely that North Korea will conduct a nuclear test in the next two to three months," 38 North said in a report.

The North has so far conducted three nuclear tests at the site in 2006, 2009 and 2013.

Speculation mounted early this year that the North could conduct a nuclear test after the regime threatened to conduct a "new form of nuclear test." But the regime did not go ahead with a test.

Last month, Pyongyang again threatened to test a nuclear device after the Third Committee of the U.N. General Assembly passed a resolution that called for referring the North to the International Criminal Court for human rights violations. (Yonhap)