European Commission President Jean Claude Juncker said Theresa May cannot begin new trade negotiations until the Brexit process is complete
The president of the European Commission has said the UK cannot negotiate its own trade deals whilst still a member of the EU.
British Prime Minister Theresa May has been looking to discuss agreements with several countries - including the US.
However in an interview on German radio, commission president, Jean Claude Juncker said she is blocked from making any agreements until after the Brexit process - likely to be 2019 at the earliest.
Mr juncker also expressed doubts as to whether EU countries will be able to maintain a united front during Brexit negotiations.
"The other EU 27 don't know it yet, but the Brits know very well how they can tackle this," Mr Juncker told Deutschlandfunk radio. "They could promise country A this, country B that and country C something else and the end game is that there is not united European front."
Mr Juncker's words come just days after British MPs approved a bill giving Mrs May permission to trigger Brexit.
On Wednesday the European Union (Notification of Withdrawal) Bill passed its final stage of voting by 494 votes to 122 - a majority of 372.
It must now go before the British House of Lords before the Brexit process can begin in earnest.
Mrs May has promised to invoke Article 50 by the end of March.
Mr Juncker, previously a conservative prime minister of Luxembourg, also told the German radio station that he would not seek a second term as EU Commission president when his current five-year term expires in 2019.
Additional reporting from IRN ...