"The North, frankly, just needs to end this provocative type of behavior. It's only inflaming tensions in the region," State Department spokesman Robert Wood said of the DPRK's nuclear weapons and ballistic missile program.
"We want to see the North live up to its international obligations," the spokesman said, adding that "We want to send a very strong, unified message to North Korea that its actions have consequences."
The DPRK conducted an underground nuclear test on May 25. In a statement released by the official news agency KCNA, the DPRK government said the "successful" test was "part of the measures to bolster up its nuclear deterrent for self-defense in every way as requested by its scientists and technicians."
The UN Security Council denounced the nuclear test as a "clear violation" of UN Resolution 1718 adopted in October 2006 after DPRK's first atomic test and said it would seek a new resolution immediately.
The 1718 resolution forbids the DPRK from conducting any future nuclear tests or missile launches.