The South Korean and U.S. defense authorities agree that the chances of another North Korean nuclear test are "very high," a senior military official said Friday.

"The assessment of South Korea and the U.S. is that chances are very high that North Korea will carry out a nuclear experiment," South Korea's deputy minister of defense, Lim Kwan-bin, told reporters after two days of meetings here with high-ranking Pentagon officials.

Lim said, however, he has no concrete evidence that the secretive communist nation is gearing up for an imminent test.

"(We) can't predict the specific timing of it, but it is believed to be possible any time," he added when asked whether Seoul or Washington has detected firm indications of nuclear activity.

Lim cited Pyongyang's track record of conducting underground nuclear tests following the launches of long-range missiles in 2006 and 2009. The North on April 12 fired a multistage rocket that fell apart shortly after blast-off.

"There are many opinions that there is a high possibility that it will go ahead with a nuclear test to make up for the failed missile launch," he said.

Lim attended the inaugural session of the Korea-U.S. Integrated Defense Dialogue (KIDD) for consultations on North Korea and major alliance issues.

The U.S. delegation was led by Acting Under Secretary of Defense for Policy James Miller and Acting Deputy Assistant Secretary of Defense for Northeast Asia David Helvey.

The allies reaffirmed a plan for tough reaction to any additional provocations by the North, Lim said.

He added the two sides agreed to a joint study and development of all the possible scenarios of North Korean nuclear threats.

"In the past, there was only broad talk of the U.S. commitment to protect the Korean Peninsula through its nuclear umbrella. There was no discussion on how they will react concretely to certain types," he pointed out.

South Korea and the U.S. will also strengthen cooperation in space and cyber-technology, he said.

(Yonhap News)