Dozens of alleged sex traffickers have been arrested in New York before this weekend's Super Bowl.
Politicians claimed that visiting football fans could order under-age prostitutes "like takeaway pizzas".
Police and FBI agents detained more than 200 people accused of crimes related to trafficking women in advance of Sunday's match, the biggest event in the US sporting calendar, said officers.
Thousands of prostitutes are expected to be shipped into the greater New York City area to cater to demand from spectators arriving to watch the Seattle Seahawks take on the Denver Broncos.
"In the last fortnight we arrested more than 200 people for prostitution-related offences, including sex traffickers, prostitutes and 'johns' who seek such services," said Detective James Duffy.
Congressmen, activists and victims told a congressional hearing in Washington this week that action was needed to stop a repeat of the estimated 10,000 women who were trafficked to Miami, Florida, for the 2010 match.
Ann Wagner, a Republican in Missouri, claimed that online advertisements now allowed fans to "order an under-age girl to their hotel room as easily as if they were ordering a delivery of pizza".
Maria Odom, a senior official at Homeland Security, told the hearing that girls and young women are "lured with false promises of well-paying jobs or are manipulated by people they trust".
Flyers designed to help workers such as public transport drivers and hotel staff spot potential traffickers and their victims have been handed out by authorities.
Miniature soaps bearing an anti-trafficking hotline number have been distributed for use in hotel bathrooms. Receptionists were told to look out for men paying in cash and checking in younger guests without luggage.
Chris Smith, the New Jersey Republican who is chairman of the congressional committee that oversees global human rights, cautioned that like other big sporting events, the Super Bowl "acts as a sex-trafficking magnet". Advocating "zero tolerance" for what he called "modern-day slavery", he said: "All of us must do our part to protect the women and girls."