HAVANA -- A leading U.S. Democratic senator said Saturday that Cuba is making progress on reform, but much remains to be done, including opening a U.S. embassy in the country.

Sen. Patrick Leahy of Vermont was leading a bipartisan delegation to the island to meet with top government officials, business leaders, diplomats and Cuban citizens to measure the pace of economic and social change, and to determine the status of talks on detente more than five decades after ties were broken off.

"I see a new, very positive change in Cuba," Leahy said during a news conference at a hotel in central Havana. "Obviously we still have differences, but I look forward to the United States being able to have a real embassy here."

Since the late 1970s, the United States and Cuba have operated diplomatic missions called interests sections in each other's capitals. The missions are technically under the protection of Switzerland, and do not enjoy the same status as full embassies.

The two countries have been negotiating the reestablishment of embassies following the Dec. 17 announcement that they would move to restore ties, but six months later no agreement has been reached.

Nor was there an embassy announcement on Saturday, although Leahy and the other two members of the delegation, Republican Sen. Dean Heller of Nevada and Democratic Sen. Ben Cardin of Maryland, said they were confident it will happen in the near future.

They met Friday with Cuba's first vice-president, Miguel Diaz-Canel, and other officials, but did not elaborate on the content of their discussions.

Cardin said the delegation made clear to Cuban officials that the path to normalization must include dealing with thorny issues where the U.S. and Cuba have serious disagreements, such as human rights.

"For normal relations to move down a productive path, it's critically important for Cuba to recognize that it is out of step today with international human rights issues," Cardin said.

The senators were scheduled to visit the eastern city of Santiago before returning to the United States.