CARACAS—Venezuelan President Nicolás Maduro said Thursday he would sue the Obama administration in an attempt to lift an executive order signed earlier this year that declared the South American country an extraordinary threat to U.S. national security.

“We can’t have that decree around. It’s like the Sword of Damocles here,” Mr. Maduro said in a televised address, pointing to his neck. “We’re going to file a lawsuit in the U.S. against that decree.”

He said the suit would expose the “international illegality” of President Barack Obama’s March 9 order, which also slapped sanctions on seven Venezuelan government officials accused of committing rights abuses during a clampdown on protesters last year.

The U.S. State Department didn’t respond to emailed requests for comment.

Mr. Maduro, who said he collected 11 million signatures during a campaign condemning the decree earlier this year, didn’t give further details. He made his comments hours after Mr. Obama’s nominee for undersecretary of state, Thomas Shannon, told lawmakers in Washington that crucial Dec. 6 elections in Venezuela would determine whether Washington will take further action against the country.