Six Arab countries have called on the United Nations to extend its arms embargo on Iran.

“Iran has continued to proliferate conventional weapons and arm terrorist and sectarian organizations and movements throughout the region,” said the Gulf Cooperation Council (GCC) in a statement about a letter sent on Saturday to Turtle Bay. “It is imperative to extend those restrictions to ensure and preserve peace and stability in this region and the rest of the world.”

Iran called the GCC effort as “unrealistic.”

“The GCC is currently at the apex of its incompetence, and its unrealistic policies have rendered it ineffective,” Iranian Foreign Ministry spokesperson Abbas Mousavi told a press conference on Monday. “The council, swayed by the wrong and destructive policies and behavior of certain member states, has turned into a mouthpiece for anti-Iran elements inside and outside the region.”

The GCC letter comes as the United States is set to introduce a resolution at the U.N. Security Council this week to extend the arms embargo on Iran, which expires on Oct. 18.

China and Russia, who, like the United States, have a permanent veto on the U.N. Security Council, are expected to veto the measure—a move that the Trump administration has said would result in enacting snapback sanctions under the deal, which would include extending the arms embargo indefinitely.