By Susan Heavey and Lisa Richwine

ROCKVILLE, Md. (Reuters) - The U.S. Food and Drug Administration is enforcing its ban on flavored tobacco products and preparing to review controversial menthol cigarettes, undeterred by legal challenges from some tobacco companies.

Dr. Lawrence Deyton, the agency's tobacco chief, told Reuters on Tuesday that the lawsuits from Reynolds American Inc, Lorillard Inc and others are not slowing his work setting up the FDA's tobacco unit or taking action against products that harm the public, especially children.

"Congress is very clear what it wants me to do, I'm moving ahead. Nobody's told me not to," Deyton said in an interview at his office in one of the agency's satellite buildings in suburban Maryland, 15 miles from the main FDA headquarters.

The FDA Center for Tobacco Products, established by law in June, is charged with regulating cigarettes and other tobacco products. It will oversee manufacturing and marketing, in part by regulating ingredients and setting advertising rules.

The agency took its first major action in September, banning cigarettes that can appeal to children, such as cinnamon and chocolate flavored cigarettes.

FDA enforcement staff are out searching for violators that may try to get around the ban, Deyton said. "It is important for the world to know, yes, we've put in place this ban on flavored cigarettes, and yes, we are enforcing it."

The flavored cigarette ban is being challenged in court by several privately-held companies and distributors.

Major cigarette makers such as Reynolds and Lorillard sued the FDA in August, saying the tobacco law limited the companies' free speech rights with advertising restrictions. Altria Group Inc's Philip Morris unit, the nation's largest tobacco company and a supporter of the FDA's new oversight, is not part of the lawsuit.

MENTHOL ON THE RADAR

Another major task is setting up an advisory panel of outside experts to provide input on sensitive issues such as menthol flavoring in cigarettes.

Menthol cigarettes, with their mint-like flavor, are a top choice for black smokers, and some advocates say they entice many young people.

Congress exempted menthol from the flavored-cigarettes ban but called on the agency to study the issue, and Deyton is eager for the advisory panel's input. He hopes the panel can be appointed by year's end with a first meeting likely in February.

"Clearly menthol is on the radar scope of everybody. We'll want to... get our scientific advisory committee working on the menthol issue right away," said Deyton, who said he tried cigarettes as a teenager but never picked up a smoking habit.

Deyton came to the FDA from the Department of Veterans Affairs, where he helped curb smoking among military veterans and still sees patients once a week as a practicing physician.

Deyton and other new tobacco center employees have years of work ahead of them as they implement other aspects of the law, which has deadlines stretching out as far as 2015.

So far the FDA has met all of the law's deadlines and "I have every intent to make all the deadlines that we need to make," he said.

Three of the 12-member advisory panel's slots will be reserved for representatives of the industry, which Deyton said has been responsive. Despite the lawsuits, companies are complying with the law, having paid roughly $23 million in user fees to help fund the tobacco center's work.

"In government world, it's moving pretty fast," he said.

(Reporting by Susan Heavey and Lisa Richwine; Editing by Tim Dobbyn)