Democratic senators visiting Havana called Tuesday for a bipartisan effort in the US Congress to lift the decades-old embargo against communist Cuba.

The three senators spoke to reporters after talks on the island with Foreign Minister Bruno Rodriguez and Josefina Vidal, Cuba's chief negotiator in talks with the US aimed at normalizing relations.

"I think there is clearly interest in Cuba in lifting the embargo," said Minnesota Senator Amy Klobuchar, the lead sponsor of legislation introduced this month to end the 1962 sanctions. "The issue will be in the US."

"One of the reasons we came on this trip was that we could go back and tell our colleagues what we've seen: That there are more and more people engaged in private sector business, that there is an entrepreneurial spirit here," she said.

"The people want to see better relations with the US."

US President Barack Obama urged Congress last month to put an end to the embargo, a key hurdle in efforts to normalize relations after a half-century of Cold War acrimony.

Cuban President Raul Castro said last month that ending the "blockade," along with returning the US naval base in Guantanamo to Cuba and removing his country from a list of state sponsors of terrorism, were the conditions to normalize relations.

But Republicans, who hold the majority in both chambers of Congress, have voiced reluctance to remove the embargo.

Missouri Senator Claire McCaskill said the potential economic benefits to US businesses and farmers could have an influence on lawmakers.

She said the people in her state most interested in doing business with Cuba are mostly Republicans, not Democrats.

"This is the business an agricultural communities that might have the most influence on helping us to make this bi-partisan effort more successful," McCaskill said.

Obama has already lifted some trade and travel restrictions, but the bulk of the sanctions -- like the prohibition of US tourism in Cuba -- remain in place and can only be removed by Congress.