Iranian President Mahmoud Ahmadinejad is set to face angry protests during his visit to New York this week for the United Nations General Assembly.
United Against Nuclear Iran, an advocacy group, has demanded that managers of the upscale Warwick Hotel refuse to host Ahmadinejad and his delegation and have urged a boycott of the international hotel chain.
"Ahmadinejad is the leader of a criminal regime allied with Al-Qaeda and other terrorists, and guilty of atrocious human rights violations," UANI president Mark Wallace said in a statement.
The group has also paid for a billboard to be placed near New York's famed Times Square showing Ahmadinejad and stating: "As we remember 9/11 ten years later, Al-Qaeda's silent partner is coming to New York."
Iran has denied harboring Al-Qaeda militants, and conclusive evidence has never emerged of a link between Tehran and the extremists who attacked New York and Washington on September 11, 2001.
But Western countries have repeatedly accused the Islamic republic of seeking to develop an atomic weapon -- charges Tehran has vigorously denied.
Tehran has been hit by a series of UN sanctions for its refusal to rein in its controversial uranium enrichment program.
New York's Columbia University was hit with a firestorm of controversy last week after reports that a student group would dine with Ahmadinejad, which the New York Post tabloid described as dinner with a "madman."
The student group, called the Columbia International Relations Council and Association, or CIRCA, later said the dinner was only tentative. Members of CIRCA did not respond to requests for comment.
Ahmadinejad is due to address the UN General Assembly on Wednesday and hold a press conference Friday.
Tehran has not confirmed whether the dinner with students will take place, but Iran's mission to the UN did not rule it out.
"Each year, the president attends meetings with the different classes of the American people who are interested in meeting him, and his meeting with the students of different universities is part of the same plan which happens (at a different place and with a different group) every year," the mission said in a statement carried by Iran'ssemi-official FARS news agency.
Iranian media reported last week that Ahmadinejad was planning to bring a gift for delegates at the UN: a book detailing the "injustices" suffered by Iran during its World War II-era occupation by Britain and the Soviet Union.
Ahmadinejad has repeatedly sparked protests and provoked anger during his annual visits to the UN General Assembly.
Last year he sparked fury when he accused the United States of staging the 9/11 attacks in his speech at the assembly.
In 2009 a dozen delegations, including the United States and France, staged a walkout to protest his fiery speech to the assembly, which they branded as "hateful and anti-Semitic."