A showdown looms after Republicans in the House of Representatives introduced a joint resolution on Tuesday seeking to block the Obama administration's nuclear agreement with Iran.

Rep. Ed Royce, chairman of the House Foreign Affairs Committee, filed House Joint Resolution 64, to prevent the implementation of the deal which President Obama transmitted to the US Congress last July 19.

Last month, President Obama defended the deal saying it "actually closes off Iran's pathway to a nuclear weapon."

"Today, Iran has enough nuclear material to produce up to 10 nuclear weapons. With this deal, they'll have to ship 98 percent of that material out of the country – leaving them with a fraction of what it takes to make even one weapon," he said.

Royce disagreed, saying "if this agreement goes through, Iran gets a cash bonanza, a boost to its international standing, and a lighted path toward nuclear weapons. By granting sweeping sanctions relief, we have lessened our ability to challenge Iran's conduct across the board. As Iran grows stronger, we will be weaker to respond."

House Republicans said they have 218 votes to block the Iran deal, according to a report by Fox News and the Associated Press.

The President is working to get the backing of Democrats in the House and Senate with Democrats Sen. Tim Kaine and Bill Nelson expressing their support to the agreement.

If both chambers approve to block the deal, President Obama is expected to veto it but opponents need two-thirds majority to override the veto.

"I wish the Obama administration had negotiated a verifiable, enforceable, and accountable agreement. The agreement gives Iran permanent sanctions relief, but in exchange only temporarily restrains Iran's nuclear programme," Royce said.

"But the consequences for global security from this agreement are too great. This deal gives up too much, too fast, to a terrorist state – making the world less safe, less secure, and less stable," he added.

Senator Kaine, on the other hand, said the deal is a "dramatic improvement over the status quo in improving global security. The agreement takes a nuclear weapons programme that was on the verge of success and disables it for many years through peaceful diplomatic means with sufficient tools for the international community to verify whether Iran is meeting its commitments."