INDIANAPOLIS (AP) — Indiana Gov. Mike Pence has joined 14 other Republican governors in denouncing the White House-backed nuclear deal with Iran.

In a Tuesday letter addressed to President Barack Obama, the governors said the deal would allow Iran to continue being a “state sponsor of terrorism” while doing little to guarantee the country would not obtain a nuclear bomb.

Pence also sent a letter to Indiana’s congressional delegation, urging them to oppose the deal.

The letters were sent the same day U.S. Senate Democrats announced they have enough votes to block a disapproval resolution against the nuclear deal.

Included among the GOP governors signing the letter are several presidential candidates including Wisconsin Gov. Scott Walker, Louisiana Gov. Bobby Jindal, Ohio Gov. John Kasich and Gov. Chris Christie of New Jersey.