Sixteen Republicans on the U.S. House Armed Services Committee are asking for $250 million to build a missile defense site on the U.S. East Coast, the latest in a series of efforts to fund an expanded territorial missile shield they say will help protect the United States from North Korea and Iran.

Their newest request appeared in an April 26 letter to Rep. Bill Young (R-Fla.), chairman of the House Appropriations defense subcommittee.

“The recent North Korean and Iranian threats to the United States and our allies further demonstrate the need for this Administration to take aggressive steps to modernize and increase the nation’s missile defense systems,” the letter reads.

The members also said they will authorize spending for an East Coast site and 20 interceptors when they draft a 2014 defense authorization bill this year.

The letter points to 2007-2008 statements from the then-commander of the U.S. Northern Command that an East Coast site “will have a clear and specific benefit to the defense of the United States, in particular, the Eastern third of the United States now not protected with shoot-look-shoot capability from the extant sites in Alaska and California.”

U.S. Defense Secretary Chuck Hagel said in March that the Defense Department would conduct environmental assessments for another ground-based interceptor site in the United States. The Missile Defense Agency currently has interceptors at two U.S. sites: Vandenberg Air Force Base, Calif., and Fort Greely, Alaska. Officials are investigating three locations, two on the East Coast, which they have not specified, and another at Fort Greely.

The Obama administration has previously objected to overtures requiring a missile defense site on the U.S. East Coast.

After a similar request in 2012, the White House issued a statement calling the measure “premature” because the administration had neither identified a requirement for a third U.S. missile defense site nor assessed its feasibility in the current budgetary environment.