European Union leadership puts on a brave face on Brexit day

The UK has officially left the European Union after 47 years of membership - and more than three years after it voted to do so in a referendum.

Union flags left discarded on the mud and grass at Parliament Square in London, following Brexit celebrations. Source: AP

European Union leaders have sought to put on a brave face on Brexit day, saying the remaining 27 countries united can tackle climate change and technological transformation.

Britain has left the EU after nearly half a century of close-knit co-operation, marking a victory for eurosceptics.

European Union Executive Ursula von der Leyen said the EU must focus on leading the way globally on tackling climate change, the digital revolution and migration.

"Our experience has taught us that strength does not lie in splendid isolation but in our unique union," she told a news conference.

People celebrate near the Houses of Parliament in London as the United Kingdom leaves the European Union. Source: Kydpl Kyodo

"The challenges that Europe faces and the opportunities that it can grasp have not changed because of Brexit."

After three-and-a-half years of tortuous divorce negotiations, Britain and the EU will now launch new talks on a post-Brexit relationship ranging from security to trade.

The EU told Britain on Friday it cannot expect "the highest quality access to the single market" unless it adopts EU standards on the environment, workers' rights, tax and state aid.

European Commission President Ursula Von Der Leyen. Source: EPA

"Without being a member, you cannot retain the benefits of membership," EU leaders including von der Leyen said in an op-ed published by European media.

"Without the free movement of people, there can be no free movement of capital, goods and services."

Britain is now officially a foreign country and its officials will have restricted access to EU offices and internal communications.

Prime Minister Boris Johnson championed the Brexit case. Source: Press Association

Diplomats of the EU-27 were reminded not to share information with Britain freely anymore.

In most other respects, however, there will be no immediate change.

Britain and the EU enter a transition period until the end of December, giving citizens and businesses time to adapt while the two sides try to hammer out a new relationship.

Trade, fishing rights, security and a raft of other issues are up for discussion.

with wires...