Sen. John McCain (R-Ariz.) said on Thursday that the Obama administration's decision to nix a proposed missile shield in Eastern Europe "a victory for [Russian Prime Minister Vladimir] Putin."

A Pentagon spokesperson confirmed early on Thursday that the Defense Department would scrap the missile defense system but denied that the cancellation had "anything to do with Russia."

McCain, who is the top Republican on the Senate Armed Services Committee, tweeted:

Missile Defense Shield scrapped by the Admin–reversal of our commitment 2 our allies & a victory for Putin

The missile defense system, which President George W. Bush originally proposed, would have placed radar units in the Czech Republic and interceptors in Poland in order to protect against a potential Iranian nuclear threat. Then-President Putin said that the program was instead a regional power grab by the U.S.

"This decision calls into question the security and diplomatic commitments the United States has made to Poland and the Czech Republic, and has the potential to undermine perceived American leadership in Eastern Europe," McCain said in a statement.

"Given the serious and growing threats posed by Iran’s missile and nuclear programs, now is the time when we should look to strengthen our defenses, and those of our allies," he added.

While Republicans have roundly criticized the move, the Obama administration has defended it as a tactical move to better fend off Iran. President Obama in brief remarks at White House the White House today said he contacted Russian officials to reiterate that their opposition to the previous system was "unfounded."

Cross-posted to the Briefing Room