The letter lacks any legal value and is not more than a publicity ploy, he said.

Almost 47 Republican senators in an ridiculous decision warned Iran in a letter made public on Monday that an agreement on its nuclear program that is not approved by the U.S. Congress could lapse as soon as President Barack Obama leaves the White House in less than two years.

Meanwhile Iran and the United States will resume a new round of nuclear talks on Tehran’s nuclear program in the Swiss city of Lausanne on March 15 to bridge their differences ahead of a July 1 deadline for reaching a comprehensive deal Tehran IRNA reports.

According to reports published by domestic media, the ministerial level talks will be headed by Iran’s Foreign Minister Mohammad Javad Zarif and his American counterpart John Kerry.

Deputy foreign ministers of Iran and the US as well as the European Union deputy foreign policy chief, Helga Schmid will attend the talks.

Iranian officials have made no comment in that regard yet.

Earlier on March 4, Zarif and Kerry wrapped up intense nuclear negotiations in the Swiss city of Montreux.

Head of the Atomic Energy Organization of Iran (AEOI) Ali Akbar Salehi and US Energy Secretary Ernest Moniz also attended the talks.

Representatives of Iran and the United States had also held three rounds of intense negotiations in the Swiss city of Geneva on February 22-23.

Iran and the P5+1– Britain, France, China, the United States and Russia plus Germany – are seeking to seal a comprehensive nuclear deal by July 1. The two sides have already missed two self-imposed deadlines for inking a final agreement since they signed an interim one in the Swiss city of Geneva in November 2013, IRNA reports.