A North Korean ambassador has lodged a formal complaint with the United Nations (U.N.) demanding U.S. officials ban Seth Rogen's upcoming comedy The Interview.

In the new movie, the Knocked Up actor and James Franco star as journalists who land a television interview with North Korean leader Kim Jong-un and are recruited by America's Central Intelligence Agency (Cia) to assassinate him.

A foreign ministry spokesperson has already condemned the film and called it a "wanton act of terror", but Rogen did not take the threats seriously and joked about it on Twitter.com in June (14).

The country's U.N. Ambassador Ja Song Nam has now written to the organisation's Secretary-General Ban Ki-moon, demanding he blocks the film's release.

In the letter, Ja Song Nam writes, "To allow the production and distribution of such a film on the assassination of an incumbent head of a sovereign state should be regarded as the most undisguised sponsoring of terrorism as well as an act of war.

"The United States authorities should take immediate and appropriate actions to ban the production and distribution of the aforementioned film; otherwise, it will be fully responsible for encouraging and sponsoring terrorism."

The Interview is scheduled to hit cinemas in October (14).