Washington, March 10 (RHC)-- U.S. President Barack Obama has lashed out at Republican senators for undermining his administration’s efforts in nuclear negotiations with Iran. Obama said: "I think it's somewhat ironic to see some members for Congress wanting to make common cause with the hardliners in Iran. It's an unusual coalition." The U.S. president made the comments during a meeting with European Council President Donald Tusk.

On Monday, a group of 47 Republican senators wrote an open letter to Iran, warning that the outcome of the nuclear talks would not be acceptable without Congressional approval and could be revoked when Obama leaves the White House in 2017.

The letter said a potential nuclear agreement with Iran would be a “mere executive agreement” that could be revoked “with the stroke of a pen and future Congresses could modify the terms of the agreement at any time.”

President Obama, however, said that he is confident that a potential deal would be implemented. Meanwhile, Senate Minority Leader Harry Reid slammed the Republican senators for embarrassing President Obama while the country’s commander-in-chief is in crucial nuclear talks with Iran.

Iranian Foreign Minister Mohammad Javad Zarif said the letter was just a publicity stunt without any legal value. The Iranian foreign minister told reporters that the letter has “no legal value and is mostly a propaganda ploy.”