Former Secretary of State and Democratic presidential hopeful Hillary Clinton says Iran should be held to letter of nuclear deal. Above, Clinton speaks at a fish fry, Jan. 16, 2016. in Charleston, South Carolina. Andrew Burton/Getty Images

Former U.S. Secretary of State Hillary Clinton Sunday praised implementation of the Iran nuclear deal but cautioned the Islamic Republic must be held to the letter of the agreement. The Democratic presidential hopeful, on CNN’s “State of the Union” just hours ahead of the scheduled Democratic presidential debate, said the agreement does not allow Tehran to start testing a lot of missiles.

The comments came as the Obama administration announced new sanctions against Iran for its missile tests — just one day after sanctions were lifted over Iran's nuclear program.

Clinton said she is proud of the role she played in negotiating the deal, which was reached in July between Iran and the five members of the U.N. Security Council plus Germany. The deal, which took effect Saturday, required Iran to dismantle much of its nuclear capability. The International Atomic Energy Agency confirmed Tehran had shipped 98 percent of its enriched uranium to Russia, dismantled 12,000 centrifuges and disabled its Arak nuclear reactor. As a result, sanctions were lifted.

Clinton recently called for more sanctions against Iran for testing missiles and defended that position Sunday, saying Iran cannot be allowed to “go off and test a lot of missiles that would be able to be intercontinental … and might carry a very dangerous weapon.”

“We have also made it clear from the beginning that their missile activity is still subject to the sanctions,” Clinton said. “That is part of the overall approach the administration has taken toward Iran, and I support it. So when we became aware of missile activity that is under U.N. supervision and is prohibited, it would be mistake not to make clear to Iran” that such activity is unacceptable.

“I think there might be a misunderstanding of what our whole agreement consists of,” she added, saying that if elected, she would enforce it. “There have to be consequences if Iran veers away from what it agreed to.”

On NBC’s “Meet the Press” Clinton said the U.S. will be watching Iran “like the proverbial hawk.”

“If they are violating it, they will be held accountable,” she said.

Clinton said the nuclear deal makes Iran less of a global threat and allows th U.S. to “turn our attention to some of these behaviors that are threatening.”

Clinton also said she is confident everything was done that could be done regarding Benghazi and her focus now is on preventing any future such incidents. The attack on the U.S. consulate in Benghazi, Libya, left U.S. Ambassador Chris Stevens and three other Americans dead.

On the Islamic State group, Clinton said on CNN she still thinks the United States should have armed rebels opposing Syrian President Bashar Assad early on, but “we’ll never know” if that would have prevented the growth of ISIS.