The UK will go to "the back of the queue" for trade deals with the US if Britain votes to leave the EU, Barack Obama has said.
President Obama also said a US-UK trade deal is "not going to happen any time soon," as the White House will be focusing its attention on reaching an agreement with the EU.
He suggested the US would focus on trade deals with the EU and big trade blocs.
What has the EU ever done for us?
What has the EU ever done for us?
1/7 1. It gives you freedom to live, work and retire anywhere in Europe
As a member of the EU, UK citizens benefit from freedom of movement across the continent. Considered one of the so-called four pillars of the European Union, this freedom allows all EU citizens to live, work and travel in other member states.
2/7 2. It sustains millions of jobs
A report by the Centre for Economics and Business Research, released in October 2015, suggested 3.1 million British jobs were linked to the UK’s exports to the EU.
3/7 3. Your holiday is much easier - and safer
Freedom to travel is one of the most exercised benefits of EU membership, with Britons having made 31 million visits to the EU in 2014 alone. But a lot of the benefits of being an EU citizen are either taken for granted or go unnoticed.
4/7 4. It means you're less likely to get ripped off
Consumer protection is a key benefit of the EU’s single market, and ensures members of the British public receive equal consumer rights when shopping anywhere in Europe.
5/7 5. It offers greater protection from terrorists, paedophiles, people traffickers and cyber-crime
Another example of a lesser-known advantage of EU membership is the benefit of cross-country coordination and cooperation in the fight against crime.
6/7 6. Our businesses depend on it
According to 71% of all members of the Confederation of British Influence (CBI), and 67 per cent of small and medium-sized enterprises (SMEs), the EU has had an overall positive impact on their business.
7/7 7. We have greater influence
Robin Niblett, Director of think-tank Chatham House, stated in a report published last year: “For a mid-sized country like the UK, which will never again be economically dominant either globally or regionally, and whose diplomatic and military resources are declining in relative terms, being a major player in a strong regional institution can offer a critical lever for international influence.
The US President was speaking after Downing Street talks with David Cameron, during a two-day visit which he has used to speak out in favour of continued UK membership in the EU.
However, he stressed that the referendum was a "decision for the people of the United Kingdom" and said he was "not coming here to fix any votes".
But he defended his right to offer an opinion, saying: "In democracies everybody should want more information, not less, and you shouldn't be afraid to hear an argument being made - that's not a threat, that should enhance the debate."
Outlining the choice facing the UK, the president said: "If, right now, I have got access to a massive market where I sell 44 per cent of my exports and now I'm thinking about leaving the organisation that gives me access to that market and that is responsible for millions of jobs in my country and responsible for an enormous amount of commerce and upon which a lot of businesses depend - that's not something I would probably do."
He also said the UK's membership of the EU "enhances the special relationship," because it means Washington has a trusted partner in Europe on issues including the fight against terrorism.
"Precisely because I have a confidence in the UK, and I know that if we are not working effectively with Paris or Brussels then those attacks are going to migrate to the United States and to London, I want one of my strongest partners in that conversation.
"So it enhances the special relationship, it does not diminish it."
Commenting on Barack Obama's speech, Leave.EU co-founder Richard Tice said:
"We don't have a trade deal with the United States now because we're members of the European Union.
"The proposed EU-US trade deal, TTIP, would be disastrous for British workers.
"Obama doesn’t have the authority to deny us a deal, as he will be long gone before any such proposals are on the table."
Additional reporting by Press AssociationReuse content