Sens. Booker, Warner, Heitkamp support Iran deal as backers work to block disapproval measure

FILE - In this June 10, 2015 file photo, Sen. Cory Booker, D-N.J., attends a Senate Commerce, Science and Transportation hearing on Capitol Hill in Washington. Booker announced his support for the Iran nuclear deal on Thursday, siding with President Barack Obama and bucking home-state pressures to say “no.” (AP Photo/Andrew Harnik) (The Associated Press)

FILE - In this July 16, 2015 file photo, Sen. Mark Warner, D-Va., speaks during a hearing of the Senate Banking, Housing, Urban Affairs Committee on Capitol Hill in Washington. Warner said in a statement that the Iran nuclear agreement negotiated by world powers was ``the best option for advancing the goal of keeping Iran from obtaining a nuclear weapon.” (AP Photo/Susan Walsh) (The Associated Press)

WASHINGTON – The Iran nuclear agreement gained the backing of three more senators — Cory Booker of New Jersey, Mark Warner of Virginia and Heidi Heitkamp of North Dakota.

The latest announcements on Thursday boosted supporters' hope they can block a disapproval resolution in the Senate and spare President Barack Obama from resorting to a veto.

Heitkamp said the deal is the best chance to prevent Iran from acquiring a nuclear weapon and keep America safe.

Supporters are aiming to collect 41 votes in favor, which would allow them to block a final vote on the disapproval resolution in the Senate and save Obama from exercising his veto power.

Heitkamp raised the number of backers to 37.