David Cameron said parents who force their children into an unwanted marriage will face "very tough punishments" under a new law.
The Government is making forced marriage a criminal offence, with Mr Cameron claiming the practice was "little short of slavery".
He said victims' lives were ruined by being taken away from the UK, often at a young age, and coerced into a marriage.
The Prime Minister said the issue had been tolerated as a "cultural practice" for too long and the time was right to take action.
After visiting the cross-departmental Forced Marriage Unit Mr Cameron said: "It is necessary to make this a crime because it is an absolutely abhorrent practice. It is, frankly, little short of slavery.
"You are taking 15, 16-year-old British citizens, taking them off to another country against their will, marrying them with someone against their will. That is a crime and it should be a crime.
"For too long in this country we have thought 'well, it's a cultural practice and we just have to run with it'. We don't. It's a crime.
"Listen to the stories of these women and what they've been through and how painful and difficult it was to be rescued and you know this should be a crime and treated as such by this country."
He added: "I think there should be tough punishments.
"Think what we are considering here: this is a 15-year-old girl, whipped out of school, flown to the other side of the world, introduced to the person they are going to be forced into marrying and their whole life being ruined.
"That's what we are talking about and as far as I'm concerned if you commit that sort of offence you get a very, very tough punishment."
Campaigners have warned that criminalising forced marriage altogether could deter victims from coming forward but the Government has announced an extra £500,000 of funding to help identify and support those affected.
"We need to change the culture and say loudly and clearly this is unacceptable.
"But passing a law isn't enough, we have got to make sure there is proper training for the schools and the police, we want to make sure we put resources into allowing women who want to escape forced marriages to have somewhere else to go if their family rejects them.
"There's a lot of steps we have to take but it's a really big and important move we are making today."
The Forced Marriage Unit was involved in 594 cases from January to May this year.
Some 45% involved victims under the age of 18, 87% of all cases involved a female victim and 46% had Pakistan as the country of origin.
Andrew Flanagan, chief executive of children's charity NSPCC, said the change would need to be monitored to ensure the problem was not pushed further underground.
He said: "It's welcome that the Government is focusing attention on this major issue in child protection and it's right that we are not afraid to tackle this problem head on.
"The NSPCC has always had concerns that a specific criminal law may risk making this abuse harder to uncover because victims could be afraid of criminalising their family if they speak out.
"So it's positive that the Government has listened and is looking at wider measures to support young people and ensure they will not be deterred from seeking help.
"The Government must now work closely with professionals such as social workers, teachers and police to make sure any law works in the best interests of the victims."
Freedom, a charity which campaigns against forced marriage and dishonour violence, welcomed the crackdown.
Founder Aneeta Prem said: "Forced marriage is an indefensible abuse of human rights and can result in abduction, serial rape and murder.
"Criminalising forced marriage will send out a powerful message to people that this practice is unacceptable in England and will be dealt with severely."
Shadow equalities minister Kate Green said the Government needed to make sure spending cuts did not undermine the support given to victims.
She said: "Forced marriage should never be tolerated - it is a terrible violation and can destroy people's lives.
"The law should be strengthened to build on the work done to stop forced marriage.
"The Government needs to work with experts to get the detail right and also to make sure that cuts to refuges or legal aid don't undermine the support victims need in practice."
An Equality and Human Rights Commission spokesman said: "Forcing someone to marry someone they do not wish to is a serious human rights violation. It may amount to domestic violence against women and children, even rape.
"People should get married because they want to, not because they are made to."
Sandra Horley, chief executive of national domestic violence charity Refuge, said: "It is crucial that perpetrators of this heinous act understand that forcing someone to marry is unacceptable, and that victims are able to speak out and safely access support."