U.S., Cuba to Announce Embassy Openings in Washington and Havana

— -- United States and Cuban government officials will announce on Wednesday that the two countries have reached an agreement to re-establish formal diplomatic relations and open embassies in Washington and Havana, a senior administration official told ABC News.

President Obama and Secretary of State John Kerry are expected to make the news public tomorrow.

Sources also tell ABC News the opening could come as early as the end of July.

Preparations have been underway for weeks for the Cuban Interest Section in Washington D.C. to become an embassy. Earlier this month a new flag pole was raised outside the building for the very first time. The last time a flag flew on the property in D.C. was 1961, when diplomatic ties were broken.

Last month, the U.S. removed Cuba from the list of countries supporting terrorism, where it was listed in 1982.