The U.S. and Cuba announced today the reopening of embassies in Washington and Havana for the first time in more than 50 years, marking a significant step in the renewal of diplomatic ties that began last December with an announcement from President Barack Obama.

But U.S. traders champing at the bit to enter the Cuban market will have to wait until Congress lifts the trade embargo that has been in place for over five decades. While such legislation has been introduced, Congress has yet to act on the measure.

“The acceptance of diplomatic credentials of the new ambassadors to the United States and Cuba will represent an historic return to formal diplomatic relations between the two countries,” said Paul Virtue, a partner in the law firm of Mayer Brown LLP and former general counsel of the Immigration and Naturalization Service. “But it will not have an immediate impact on the U.S. economic embargo on Cuban goods or the U.S. sanctions and export control regulations that were eased in January 2015 following the president’s announcement.

The biggest change coming with the opening of the embassies, Virtue added, is that U.S. and Cuban affairs will be handled directly and no longer through interests sections of the Swiss embassies in Havana and Washington.

The lifting of the embargo must come through an act of Congress. Such a bill has been introduced by Sen. Amy Klobuchar (D-Minn) but it has yet to be taken up by the Republican-controlled Senate Banking Committee. The bill faces opposition from both sides of the aisle, especially from members of Congress close to Cuban-American constituencies.

All of the announced Republican candidates for president, other then Sen. Rand Paul (Ky.), oppose lifting the embargo. Sen. Robert Menendez (D-N.J.) has also been vocal in his opposition to the measure.