"When you withdraw from Iraq, when you pull back the surge unnecessarily because of election cycles, [it] sends mixed messages," Graham said.

On Sunday, Obama told the American Israel Public Affairs Committee conference that "loose talk of war" only helped Iran and undermined sanctions and diplomatic negotiations.

"Now is not the time for bluster," Obama said. "Now is the time to let our increased pressure sink in."

But Graham said the president should use his meeting with Netanyahu to assure the Israeli prime minister of America's commitment to supporting its ally.

"I think the prime minister of Israel needs to be reassured that the United States recognizes Israel can make their own decisions ... as a sovereign nation and that we see things just like they do," Graham said.

"Quit talking about what Israel should or should not do. Tell the Iranians, 'Stop enriching, or else, and here's what we want you to do to prove you've stopped enriching,' " he added.

Graham said he was unconvinced sanctions could do the job alone.

"As everyone talks, they keep enriching. As their economy gets hurt, they keep enriching ... The only way to stop the Iranians, in my view, is if they believe a military strike of devastating consequences will come their way if they don't start."

The South Carolina lawmaker went on to say Iran developing nuclear capabilities was "not an acceptable choice."

"If they get a nuclear weapon, then that's something you don't want on your resume as a president," Graham said.