President Obama struck back at critics of the Iran nuclear deal Monday with a speech in San Francisco. Top Republicans and the Israeli government have denounced the agreement since it was reached Saturday night. Obama said opponents of the deal champion “tough talk and bluster.”

President Obama: “If Iran seizes this opportunity and chooses to join the global community, then we can begin to chip away at the mistrust that’s existed for many, many years between our two nations. None of that — none of that’s going to be easy. Huge challenges remain, but we cannot close the door on diplomacy, and we cannot rule out peaceful solutions to the world’s problems. We cannot commit ourselves to an endless cycle of conflict. And tough talk and bluster may be the easy thing to do politically, but it’s not the right thing for our security.”

Despite Obama’s stance, Senate Democrats said Monday they have not ruled out taking up new sanctions against Iran when Congress reconvenes next month. Iran has warned that any new sanctions would scuttle the Geneva agreement.