"The St. Patrick's Day parade (in New York) is a parade about our Irishness and not about sexuality, and I would be happy to participate in it," he said in Dublin before leaving for a six-day trip to the U.S.
Parade organizers have said gay groups are not prohibited from marching, but are not allowed to carry gay-friendly signs or identify themselves as LGBT.
Some LGBT groups plan to protest the parade along Manhattan's Fifth Avenue on Monday. Others will gather at the city's historically significant Stonewall Inn, where the gay rights movement was born, to dump Guinness beer from its shelves in protest of the beer company's parade sponsorship.
Other beer companies have joined the boycotts, with Sam Adams withdrawing its sponsorship of Boston's parade and Heineken following suit in New York.
New York's parade, a tradition that predates the city itself, draws more than 1 million spectators and about 200,000 participants every March 17. It has long been a mandatory stop on the city's political trail, and will include marching bands, traditional Irish dancers and thousands of uniformed city workers.
Several global landmarks will be bathed in green as part of a push by Ireland's tourism agency, among them Sleeping Beauty's Castle at Disneyland Paris in France, as well as the French capital's Moulin Rouge nightclub. (Better make that the Moulin Vert.)
Other locations transforming at night under green floodlights are the Petrin Lookout Tower in Prague; Rhine Falls near Zurich; the Taj Mahal in India; the London Eye Ferris wheel; Niagara Falls; the Las Vegas welcome sign; New York City's Empire State Building; the Leaning Tower of Pisa; Sydney Opera House in Australia; and both the Giza pyramids and the Sphinx in Egypt.