Sen. Marco Rubio said Monday, July 20, will go down in history as President Obama's "Capitulation Day," as it marked the day that the United Nations Security Council voted to lift international sanctions on Iran in returning for limits on its nuclear program, and when embassies were opened in Washington and Havana.

"History will remember July 20, 2015, as Obama's Capitulation Monday, the day two sworn enemies of the United States were able to outmaneuver President Obama to secure historic concessions," the Florida Republican said in a statement.

Events at the United Nations, Washington and Havana, he said, are proof that "we have entered the most dangerous phase of the Obama presidency." He accused Obama of "flat-out abandoning America's vital national security interests to cozy up to the world's most reprehensible regimes."

The U.N. Security Council vote took place Monday morning, U.S. time, in Brussels. The Obama administration moved forward with the vote despite sharp bipartisan resistance in Congress. The top Republican and Democrat on the Senate Foreign Relations Committee, Sen. Bob Corker, R-Tenn., and Sen. Ben Cardin, D-Md., have urged the administration not to move forward with the vote, arguing that it undercuts Congress and the Senate's Constitutional mandate to review all international treaties.

Corker called the decision to seek U.N. approval before Congress has a chance to begin its 60-day review of the Iran deal an "affront" to the American people and Congress. Cardin, just Sunday, said the administration should reverse course and allow Congress to weigh in on the deal before seeking U.N. approval.

The White House and Secretary of State John Kerry say quick approval at the U.N. makes sense because the U.S. negotiated the Iran deal with its other U.N. P5+1 partners, namely the U.K., France, Germany, China and Russia. The administration argues it is not undercutting Congress because the sanctions won't be lifted for 90 days, allowing U.S. lawmakers their 60 days review process. The U.N. vote also will not impact U.S. sanctions.

Kerry will brief reporters on the embassy openings at 1:45 p.m. The Cuban delegation will meet with their counterparts in the U.S. today for the first time in more than 50 years and plan to visit Capitol Hill later today.

A Cuban flag was hoisted in the State Department's lobby this morning will no ceremony or fanfare. State Department spokesman John Kirby said the agency routinely flies the flag of countries once the U.S. formally recognizes diplomatic ties with them.