The State Department will start flying the Cuban flag in its lobby on Monday, an act that symbolizes the re-establishment of normalized relations between the U.S. and Cuba for the first time in more than 54 years.

Normal diplomatic relations between the two countries were made possible after President Obama agreed to remove Cuba from the list of terrorist-sponsoring nations. Cuba had pressed for that as a condition, and when that demand was granted, the deal quickly came together to set up official embassies in each other's countries.

On Monday, the Interests Sections that the U.S. and Cuba have in their respective countries will legally become embassies. State Department spokesman John Kirby said that when the U.S. formally recognizes a new country, it routinely flies the flag of that country at State's Washington, D.C., headquarters.

"It will be hung in the atrium of the C Street entrance of the building," Kirby said. "It will be done early in the morning so as to allow for the give and take of the people coming in and out of the building."

When pressed on exactly when the flag would be hung, he said "very early." But he said there is no official ceremony when this happens, and there never has been one.

The last time State flew a new flag was in 2011, when it added South Sudan's flag, Kirby said.

Early Monday afternoon, Secretary of State John Kerry will meet with Cuban Foreign Minister Bruno Rodriguez Parrilla, and will hold a joint press availability once the meeting ends.

The Cuban Interests Section in Washington will become an embassy on Monday, and Kirby said senior State Department officials would be there for that event.

Kerry is expected to travel to Cuba soon, but Kirby said he had no information on when that trip would happen.