U.S. Defense Secretary Chuck Hagel says North Korean provocations present a "real and clear danger and threat" to American allies and the U.S. homeland.

Hagel made the remark at the National Defense University in Washington on Wednesday as he noted that North Korean leader Kim Jong-un has threatened to shell the South Korean capital of Seoul and to launch missiles at Guam, Hawaii and the western United States.

He said North Korea has a nuclear capacity and missile delivery capacity now, adding that Washington takes those threats seriously.

Hagel said the U.S. is doing everything it can, including working with China among others, to defuse the situation on the Korean Peninsula.

Hagel said he spoke with new Chinese Defense Minister General Chang Wanquan and discussed the North’s nuclear threats. The secretary said China certainly doesn’t want “a complicated and combustible situation to explode into a worse situation” and neither does the U.S.