Washington - Nearly three-fourths of Americans think the United States should have diplomatic ties with Cuba, but they're not sure how far to go in lifting sanctions, according to an Associated Press-GfK poll released Monday as full diplomatic relations between the two countries were formally restored."Relations between Cuba and the US I think are long overdue. There's no threat there," said Alex Bega, 30, of Los Angeles. "I think the sanctions we have on them are pretty much obsolete."The resumption of normal ties ended decades of acrimony between the two nations that was hardened when President John F Kennedy and Cuba's Fidel Castro fought over Soviet expansion in the Americas. The new diplomatic status, however, does not erase lingering disputes, such as mutual claims for economic reparations, Havana's desire to end the more than 50-year-old trade embargo and the U.S. push for Cuba to improve human rights and democracy.The new poll also found that 58 percent of Americans approve of President Barack Obama's handling of the US relationship with Havana while another 40 percent disapprove. By contrast, only 39% approve of his handling of the US role in world affairs more generally, while 59% disapprove.Iran’s nuclear programme"I just disapprove of his politics in general," said Julie Smith, 40, a university administrator from Bowling Green, Kentucky. "I just don't think that us trying to improve relations with Cuba is beneficial to the United States."Respondents were split on what to do about the sanctions on Cuba. Forty-eight percent thought they should be decreased or eliminated entirely while 47% favoured keeping them at their current level or increasing them. Five percent didn't answer.The story was different when it came to Iran.Seventy-seven percent said they thought sanctions on Tehran should be kept where they are or increased, according to the poll, which was conducted just days before the US signed an agreement to curb Iran's nuclear programme in exchange for economic sanctions relief.Under the agreement, Iran's nuclear program will be curbed for a decade in exchange for potentially hundreds of billions of dollars' worth of relief from international sanctions.There is some momentum in Congress to lift the trade embargo on Cuba.Brutal behaviourDemocratic Senator Amy Klobuchar backs a bipartisan bill in the Senate to lift the embargo, which she said must be done for the US to avoid losing investment opportunities that will come with loosening of travel restrictions to the island."Once millions of American tourists are going, they will need places to stay and they will need food to eat. ... So when they come, they are going to be starting to sleep in Spanish hotels and eat German foods because those countries will be able to supply what they need in the tourism industry, not to mention the computers and Wi-Fi and everything else," Klobuchar said in an interview.She predicted the legislation, which has 20 co-sponsors so far, would pass, although maybe not this year. "I know there are some people who have long been opposed to this," she said.Democratic Sen. Bob Menendez, who is Cuban-American, thinks the Obama administration's work to restore relations is an attempt to validate the Castro regime's "brutal behaviour"."I remain deeply concerned with ongoing human rights violations in Cuba," Menendez said on Monday. "There have been over 2 800 political arrests on the island this year alone."The AP-GfK Poll of 1,004 adults was conducted online July 9 to July 13, using a sample drawn from GfK's probability-based KnowledgePanel, which is designed to be representative of the US population. The margin of sampling error for all respondents is plus or minus 3.4 percentage points. Respondents were first selected randomly using phone or mail survey methods, and later interviewed online. People selected for KnowledgePanel who didn't otherwise have access to the internet were provided access at no cost to them.