President Obama reiterated his call today for Congress to hold off on imposing any new sanctions against Iran, just one day after a final deal for Iran to curb its nuclear program was announced.

"It's going to be difficult. It's going to be challenging, but ultimately, this is how diplomacy should work," Obama said at the end of a bilateral meeting with the Prime Minister of Spain Mariano Rajoy.

"My preference is for peace and diplomacy, and this is one of the reasons why I've sent a message to Congress that now is not the time for us to impose new sanctions; now is the time for us to allow diplomats and technical experts to do their work," he later added. "We will be able to monitor and verify whether or not the interim agreement is being followed through on, and if it is not, we'll be in a strong position to respond. But what we want to do is give diplomacy a chance and give peace a chance."

Secretary of State John Kerry announced Sunday that a six-month interim agreement with Iran will begin on Jan. 20, at which point Iran will grant International Atomic Energy Agency inspectors daily access to two major power plants and will halt enrichment of Uranium to 20 percent. Iran is expected to receive about $7 billion over the course of the deal.

"While implementation is an important step, the next phase poses a far greater challenge: negotiating a comprehensive agreement that resolves outstanding concerns about the peaceful nature of Iran's nuclear program," Kerry said Sunday.

On Wednesday, President Obama is set to meet with the Senate Democratic caucus at the White House, a meeting which will include Sen. Bob Menendez, D-N.J., one of the architects of the plan to impose new sanctions against Iran.