U.S. Defense Secretary Chuck Hagel has sent a strong warning to North Korea as it prepares to a launch a mid-range ballistic missile.

During a news conference Wednesday on the Pentagon’s budget plans for next year, Hagel said North Korea has been skating very close to a dangerous line with its bellicose rhetoric and actions. He said Pyongyang's "actions and words have not helped defuse a combustible situation."

Sitting next to Hagel, Chairman of the U.S. Joint Chiefs of Staff, General Martin Dempsey, said the U.S. is posturing for a worse case scenario and making active preparations to defend its allies.

In London, the foreign ministers of the G8 countries have been discussing ways to block North Korea’s provocations. Britain wants to send a united message to the North while Russia has expressed willingness to pressure Pyongyang.