President Obama early Tuesday morning defended the agreement between world powers and Iran aimed at curbing Iran's nuclear program, and warned that he would protect the deal by vetoing any disapproval resolution that comes out of Congress.

"I will remind Congress that you don't make deals like this with your friends," he said, referring to nuclear agreements reached with Russia when it was still the Soviet Union. "I will veto any legislation that prevents the successful implementation of this deal."

Obama's remarks were an attempt to pitch the deal to a skeptical Congress, and he warned that the agreement is far better than any other alternative out there, which could include a rush to war.

"Without a diplomatic resolution, either I or a future U.S. president would face a decision about whether or not to allow Iran to obtain a nuclear weapon or whether to use our military to stop it," Obama said during his remarks at the White House. "Put simply, no deal means a greater chance of more war in the Middle East."

He said that the deal "is in line with a tradition of American leadership" in the world and helps reduce the proliferation of nuclear weapons, particularly in the Middle East, "the most volatile region in the world."

Obama assured the world that intrusive inspections that would prevent Iran from circumventing the agreement's prohibitions on its nuclear program are built into the deal. "This deal is not built on trust; it is built on verification," he said.

The talks involving the U.N. Security Council: China, France, Great Britain, Russia and the U.S., plus Germany, that negotiated with Iran took almost two years to complete. As a deal looked imminent in final days of talks in Vienna, criticism on Capitol Hill and from Israel intensified.

Congressional Republicans and some Democrats believe Obama was conceding too much to reach a final deal, and many were expected to criticize the decision to allow the United Nations conventional arms embargo to be lifted after five years. Israeli Prime Minister Benjamin Netanyahu called the deal a "mistake of historic proportions" that will give Iran a "sure path to nuclear weapons."

Still, Obama said it would be "irresponsible to walk way from this deal" given that it constrains Iran and helps stabilize the Middle East. He said he "welcomes a robust debate in Congress on this issue and I welcome scrutiny of the details of this agreement."

Under legislation passed earlier this year, Congress has the ability to stop the deal by passing a resolution disapproving of it. It may end up being easy to pass that resolution, but Obama would then have a chance to veto it. If that happens, his veto could only be overridden by a two-thirds majority vote in both chambers.

With Republicans squarely against the agreement, the focus is likely to shift to Democrats in the House and Senate to see how many of Obama's own party will come out against the deal.