“We want to push back against the extremists,” added Imam Feisal, 61.

Although organizers have sought to avoid publicizing their project because they say plans are too preliminary, it has drawn early encouragement from city officials and the surrounding neighborhood.

Mayor  http://topics.nytimes.com/top/reference/timestopics/people/b/michael_r_bloomberg/index.html?inline=nyt-per - Michael R. Bloomberg  said through a spokesman that Imam Feisal told him of the project last September at a celebration to observe the end of Ramadan. As for whether Mr. Bloomberg supported it, the spokesman, Andrew Brent, said, “If it’s legal, the building owners have a right to do what they want.”

The mayor’s director of the  http://www.nyc.gov/html/imm/html/home/home.shtml - Office of Immigrant Affairs , Fatima Shama, went further. “We as New York Muslims have as much of a commitment to rebuilding New York as anybody,” Ms. Shama said. Imam Feisal’s wife, Daisy Khan, serves on an advisory team for the  http://www.national911memorial.org/site/PageServer?pagename=New_Home - National September 11 Memorial and Museum , and Lynn Rasic, a spokeswoman for the memorial, said, “The idea of a cultural center that strengthens ties between Muslims and people of all faiths and backgrounds is positive.”

Those who have worked with him say if anyone could pull off what many regard to be a delicate project, it would be Imam Feisal, whom they described as having built a career preaching tolerance and interfaith understanding.

“He subscribes to my credo: ‘Live and let live,’ ” said Rabbi Arthur Schneier, spiritual leader of  http://topics.nytimes.com/top/reference/timestopics/organizations/p/park_east_synagogue/index.html?inline=nyt-org - Park East Synagogue  on East 67th Street.

As a Sufi, Imam Feisal follows a path of Islam focused more on spiritual wisdom than on strict ritual, and as a bridge builder, he is sometimes focused more on cultivating relations with those outside his faith than within it.

But though the imam is adamant about what his intentions for the site are, there is anxiety among those involved or familiar with the project that it could very well become a target for anti-Muslim attacks.

Joan Brown Campbell, director of the department of religion at the  http://www.ciweb.org/ - Chautauqua Institution  in upstate New York and former general secretary of the  http://www.ncccusa.org/ - National Council of Churches of Christ U.S.A. , who is a supporter of Imam Feisal, acknowledged the possibility of a backlash from those opposed to a Muslim presence at ground zero.

But, she added: “Building so close is owning the tragedy. It’s a way of saying: ‘This is something done by people who call themselves Muslims. We want to be here to repair the breach, as the Bible says.’ ”

The  http://topics.nytimes.com/top/reference/timestopics/organizations/f/federal_bureau_of_investigation/index.html?inline=nyt-org - F.B.I.  said Imam Feisal had helped agents reach out to the Muslim population after Sept. 11. “We’ve had positive interactions with him in the past,” said an agency spokesman, Richard Kolk. Alice Hoagland of Las Gatos, Calif., whose son, Mark Bingham, was killed in the hijacked plane that crashed in Pennsylvania, said, “It’s quite a bold step buying a piece of land adjacent to ground zero,” but she said she considered plans for the site “a noble effort.”