AMSTERDAM - The mayor of Amsterdam married five American-Dutch gay couples on Saturday in an implicit criticism of the lack of same-sex marriage in many U.S. states.

Tens of thousands of spectators cheered as Mayor Job Cohen performed the ceremony on a cruise around the city's canals to celebrate the high point of the city's gay pride festival. Eight years ago Cohen presided over the first legal Dutch gay marriage.

All five couples had at least one partner from New York, where a battle over the legalization of gay marriage rages on.

For me it's a message to New York, the most liberal state, the most hip state, to get with it, said Ira Siff, an opera professional from New York who was about to marry his partner, opera singer Hans Heijnis.

The New York-Amsterdam connection is much in the news this year, with the cities celebrating a 400-year relationship in 2009. Cohen called the couples a figurehead for that bond.

Your transatlantic love is proof of the lasting connection between old and new Amsterdam, Cohen said in the service.

In 1994, Dutch parliamentarian Boris Dittrich introduced the Netherlands' first gay marriage bill. Now an advocacy director at Human Rights Watch in New York, he was on the boat as a guest of the city.

We want to show to the American public that gay couples cannot get immigration, cannot get equal rights like heterosexual couples can, Ditttrich said.

The couples and activists want to be able to legally marry and to have that bond recognized on a state and a federal level.

Hope is all we've got, said New Yorker Patrick Decker, whose wedding to Dutch-born partner Stephan Hengst started the celebration.

Gay marriage is not legal under New York state law, but the state does recognize gay marriages consecrated elsewhere where it is legal. So the couples wed on Saturday will be treated as married for certain purposes by the state.

(Editing by Robin Pomeroy)