Responding to questions posed by journalists if he agreed with German finance minister Wolfgang Schaeuble who earlier told Bloomberg that Britain would find "open doors" if it changed its mind, Macron said: "The door of course is still open as long as Brexit negotiations have not been concluded, but a sovereign decision to leave the European Union has been taken and I respect that decision".
After their press conference the two leaders headed to the Stade de France to watch a friendly match between the French and English football teams.
After talks with British Prime Minister Theresa May in Paris, French President Emmanuel Macron said both countries agreed that social networks were not doing enough to stamp out terror propaganda. "But until negotiations come to an end, there is always a chance to reopen the door", Macron continued.
The British Prime Minister claimed, "I confirmed to President Macron that the timetable for the Brexit negotiation remains on course and will begin next week".
On Tuesday, Michel Barnier, the EC's chief Brexit negotiator, also urged for talks to start "very quickly" because "time is passing, and we have to work to the timeline fixed by the treaty", adding that he could not "negotiate with myself".More news: 'White' London mosque attacker identified, security up
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She said the British and French campaign was aimed to "ensure the internet cannot.be used to host the radicalising material that leads to so much harm".
The Prime Minister flew to the French capital after breaking off from talks with the Democratic Unionist Party to shore up her minority government following last week's disastrous election results.
May said the process would lead to "an arrangement for Brexit which will be the interests of the United Kingdom and the remaining 27 members of the European Union".
Macron said Internet companies would be asked to do more to remove content promoting terrorism, access to encrypted content on online messaging systems would be widened, and co-operation with the United States on online content would be improved.
The UK and France are also to develop plans to create a new legal liability for tech companies which fail to take action against unacceptable content.