Cuba’s official embassy in Washington will open its doors Monday as the island nation fully restored diplomatic relations with the U.S. at midnight. The U.S. Interests Section in Cuba has also transitioned into an official diplomatic mission, marking the first time the two countries have operated full-fledged embassies in Havana and Washington since they cut ties in 1961. Foreign Minister Bruno Rodriguez will lead a ceremony to memorialize the occasion at the newly upgraded embassy with some 500 guests, including a 30-member delegation of Cuban leaders. Rodriguez is expected to meet with U.S. Secretary of State John Kerry later in the day. The U.S. Interests Section in Havana is not expected to raise an American flag until Kerry visits to lead a formal ceremony in August.