Washington, Sep 9 (IANS): Three more US Democratic senators on Tuesday said they would support the nuclear agreement with Iran, bringing the number of lawmakers who have announced their decision to favour the deal to 41.

The three senators who said they would back the agreement were Gary Peters of Michigan, Richard Blumenthal of Connecticut and Ron Wyden of Oregon, Xinhua reported.

"Despite my serious concerns with this agreement, I have unfortunately become convinced that we are faced with no viable alternative," Peters said.

"While this is not the agreement I would have accepted at the negotiating table, it is better than no deal at all," Blumenthal said.

"This agreement with the duplicitous and untrustworthy Iranian regime falls short of what I had envisioned, however, I have decided the alternatives are even more dangerous," Wyden wrote.

The decisions came on a day when lawmakers reassembled after a month-long recess.

Six Democrats remained undecided, with 38 having openly favoured the deal before the three senators' announcements on Tuesday.

If numbers hold, the 41 senators will be enough to block a Republican-backed resolution to disapprove the deal and will save the President Barack Obama's need to use his veto.

US lawmakers have until September 17 to vote on the deal with a resolution of disapproval. Many of the lawmakers, especially Republicans, believe that the deal made too many concessions to Iran and it cannot stop Iran from building nuclear weapons.

The nuclear agreement was reached in July after extensive negotiations between Iran and the P5 1 group, namely Britain, China, France, Russia, the US and Germany.

"This deal blocks every way, every pathway that Iran might take in order to develop a nuclear weapon," Obama said last week.

The president has vowed to veto any congressional attempt to block the agreement's implementation. It requires approval of two-thirds lawmakers in both the House and the Senate to override the veto.