British Prime Minister Gordon Brown condemned "in the strongest terms" a new nuclear test conducted by the Democratic People's Republic of Korea (DPRK) on Monday.
Brown said "this act will undermine prospects for peace on the Korean Peninsula and will do nothing for North Korea's security."
He described the decision to carry out the test as "erroneous, misguided and a danger to the world", Xinhua reported.
"The international community will treat North Korea as a partner if it behaves responsibly" he added. "If it does not, then it can expect only renewed isolation."
In a statement released by the official news agency KCNA, the DPRK said on Monday it has successfully conducted "one more" underground nuclear test earlier in the day. But the brief statement did not give any details about the test, including its location. The DPRK conducted its first nuclear test in 2006.
The test came after the United Nations Security Council adopted a presidential statement in late April, condemning the April 5 rocket launch by the DPRK and demanding the country "not conduct any further launch."