Prince William_Kate Middleton
Britain's Catherine, Duchess of Cambridge (R) and her husband Prince William exit a fire station during a visit to the Valero Pembroke Refinery in south Wales, Nov. 8, 2014. Reuters/Darren Staples

U.S. journalists need to be in proper attire when the Duke and Duchess of Cambridge make their royal visit to New York City and Washington, D.C. next month, Buckingham Palace has announced.

Prince William and Kate Middleton will reportedly make the visit on behalf of the Royal Foundation, "other charities with which Their Royal Highnesses are closely associated" and the U.K. government.

The royal press office announced that journalists who wish to cover the royal family should comply with the dress code and if they failed to do so they would not be admitted to cover events on the visit. The dress code includes “smart attire for men... the wearing of a jacket and tie, and for women a trouser or skirt suit.”

“Those wearing jeans or trainers will not be admitted and casually dressed members of the media will be turned away. This also applies to technicians,” the royal family said.

The Duke and Duchess of Cambridge, both 32, will be in the Big Apple from Dec. 7 to Dec. 9 and Prince William will make a stop in Washington, D.C., while Middleton will remain in the New York City, the palace reportedly said.

Middleton is expecting her second child with Prince William and is due in April 2015. The Duchess had been suffering from hyperemesis gravidarum, an acute form of morning sickness.