Secretary of State John Kerry will travel to Cuba later this summer to reopen the US embassy in Havana, President Obama announced on Wednesday.

The post is set to open on July 20, after the Cuban government opens an embassy in Washington, according to White House deputy national security adviser Ben Rhodes. Diplomatic relations between the two countries have not existed in more than 50 years.

“This is a historic step forward in our efforts to normalize relations with the Cuban government and people,” President Obama briefed reporters on Wednesday.

He added that the US had been “clinging to a policy that was not working.”

“Instead of supporting democracy and opportunity for the Cuban people, our efforts to isolate Cuba, despite good intentions, increasingly had the opposite effect,” Obama said.

Secretary Kerry’s visit to Cuba will mark the first visit by America’s top diplomat to the island nation since 1945.

“The United States and Cuba continue to have sharp differences over democracy, human rights, and related issues,” Kerry said on Tuesday, delivering a statement from Vienna where the latest round of nuclear talks with Iran have been ongoing.

“But we also have identified areas for cooperation that include: law enforcement, safe transportation, emergency response, environment protection, telecommunications, and migration,” the Secretary of State added.

Noting those areas of common interest, President Obama said today’s announcement is “not merely symbolic.”

The recalibration of relations with Cuba was first announced last December in a move that drew ire from lawmakers, who–for political, personal, and ideological reasons—still hold tremendous animosity toward the Castro government.

Reacting on Tuesday, Rep. Ileana Ros-Lehtinen (R-Fla.), the chair o the House Foreign Relations Committee, said, “Opening the American Embassy in Cuba will do nothing to help the Cuban people and is just another trivial attempt for President Obama to go legacy shopping.”

Other lawmakers, however, were more optimistic.

“[email protected] announcement on #Cuba embassies is a major milestone. Now, it’s time to end the embargo & #travelban!” tweeted Rep. Barbara Lee (D-Calif.).

As a precursor to establishing full diplomatic relations, the administration removed Cuba from the state sponsors of terrorism list in May. Prior to that, it eased travel and economic restrictions.

The White House will have to rely on Congress, however, to complete the transformation in Cuban relations, since only lawmakers have the power to lift the 55-year-old embargo. Legislation to do that was introduced this year by Sens. Jeff Flake (R-Ariz.) and Patrick Leahy (D-Vt.).