The situation had been highlighted by David Miliband, Britain's foreign secretary, who had raised the circumstances of a case in Pakistan ahead of a visit he is due to make to the country on Wednesday.
In an article in Britain's Sunday Times newspaper at the weekend, Miliband said that the UK was taking a tougher stand against forced marriage, describing the practice as "a stain on those who carry it out, those who condone it and also those who ignore it".
He recounted the tale of British diplomats rescuing a 15-year-old girl last week from a village near Mirpur in northern Pakistan, where she was being held prisoner and was beaten by her father to get her to agree to marriage.
So far this year, the FMU has handled more than 1,500 reports of forced marriage and diplomats across the world have helped more than 400 people facing possible forced marriage, or being made to sponsor an immigration visa after marriage has taken place, Miliband said.
Under the new laws, those who do not comply with court orders related to forced marriage, which can be sought by a victim, a friend or the police, could face jail.
"This new law is a powerful tool that will help ensure that no one is forced into marriage against their will and those already in such marriages will receive protection," Bridget Prentice, a junior justice minister said.
"Our policies reinforce that hope and send a clear message that we are committed to providing support and help to victims and that violence of any kind will not be tolerated."
Shaminder Ubhi, the director of the Ashiana network, which works with victims of domestic violence, noted that while not everyone would want to use the legislation, "this act sends a clear message that forced marriage will not be tolerated and perpetrators will be held accountable".