North Korea has warned that a naval blockade enforced by the U.S. will be seen as an act of war.

The North's foreign ministry spokesman told state-run KCNA Thursday that the U.S. is taking a dangerous step towards nuclear war by "attempting to create extreme sanctions on the North through measures such as a naval blockade at the United Nations Security Council high-level meeting on the 15th."

The spokesman warned that a naval blockade would be a gross violation of national sovereignty and dignity, and that the regime will respond with "merciless measures" to defend itself.