LEADERS of the European Union have congratulated Boris Johnson on his election victory, but warned that a huge challenge lay ahead in trying to secure a trade agreement between Europe and the UK in just 11 months.

Most pacts take years to conclude and the lack of time means that priorities will have to be set.

“It’s not only about a trade agreement but also speaking about education ... about transport, about fisheries, about sectorial questions,” said European Commission president Ursula von der Leyen, after the meeting in Brussels. She added: “Many, many other fields are in the portfolio to be negotiated.”

German Chancellor Angela Merkel agreed that concluding an agreement on future ties will be “very complicated” and that “what will matter above all is that we work very quickly and precisely”.

On January 31, Britain is set to become the first country to leave the world’s biggest trading bloc.

The National: The UK is the only country to have ever decided to leave the EUThe UK is the only country to have ever decided to leave the EU

Many EU leaders are breathing sighs of relief that the Brexit saga is finally coming to an end more than three years after Britons voted to leave, but just as many are saddened at the departure of a heavyweight member state. The sense of relief was evident among European business groups, although it was tinged with some regret.

Uncertainty over Britain’s future was a big business concern and some companies have shifted operations out of the UK.

READ MORE: Boris Johnson to push Brexit deal through Commons next week

Questions remain over the post-Brexit relationship and whether tariff-free trade between the UK and EU will continue after a departure transition period expires at the end of next year.

French President Emmanuel Macron said: “My hope is that the UK remains an ally, friend and extremely close partner.

“But on the condition that we manage to define the rules for a loyal relationship. If there is no regulatory convergence, we will not be able to conclude an ambitious trade agreement.”

Though the pathway to Britain’s departure by January 31 is reasonably clear, the future relationship between the country and the EU is not and discussions on that can only begin after Britain formally leaves.

Charles Michel, the new EU Council president, added: “We are ready.

“The European Union will negotiate in order to have close co-operation in the future with the UK.”