Obama afraid to come to Congress about Iran: Corker

President Barack Obama's administration is not coming to Congress with its plans to reach a nuclear deal with Iran because it is afraid to explain itself to lawmakers, Sen. Bob Corker said Friday.

"We know that for some time, the U.S. position has been moving towards the Iranian position and not vice versa. We've all been very concerned about it," the Republican chairman of the Senate Foreign Relations Committee said in an interview on CNBC's "Squawk Box."

The concern stems from the length of time an agreement would last, he said. The talks have recently been on course to yield a deal that would limit Iran's nuclear capability for 10 years, a period some say is too short.

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Participants in the negotiations have suggested the talks are progressing toward an agreement, which would pave the way for the United States and the United Nations to lift sanctions on Iran.

Corker said the White House would have the ability to deal with the situation as it saw fit if it were only seeking to address sanctions imposed by the executive branch or the U.N. Security Council. The problem, he said, is the president is going over Congress's head to lift sanctions that the legislative body imposed on Iran, which he said brought Iran to the negotiating table.

"All we're saying is, 'Mr. President, please, don't take actions that do away with the congressionally mandated sanctions without coming and getting our approval,'" the Tennessee Republican said.

"It appears they want to go straight to the United Nations Security Council and try to bind Congress by going that route. Obviously we think that's inappropriate."

Corker is one of seven Senate Republicans who did not sign a letter to Iran that warned any deal reached by the Obama administration over that country's nuclear program could be overturned in the future.

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Corker said he is instead focused on pushing through bipartisan legislation that would subject any nuclear deal with Iran to congressional review.

Obama has said he would veto that legislation, but faces the threat that Democrats will align with Republicans to override his veto. However, the move has reportedly lost some support among congressional Democrats, who are seen rallying behind the president following the GOP's decision to directly address Iran.

Some see that decision as a breach of diplomatic protocol and a bridge too far. Sen. John McCain, R-Ariz., chairman of the Senate Armed Services Committee, acknowledged that the move was perhaps not the best way to tell Iran that Congress will play a role in the negotiations.