Brexit: Britain formally leaves EU as clock chimes 11 p.m.

Jan. 31 (UPI) -- Britain officially left the European Union on Friday in a largely symbolic but historic moment, after more than three years of debate and bitter division over an uncertain future.

Britons counted down to 11 p.m. to mark the end of 47 years of membership, and political and economic integration into the European community. It's first time any country has voluntarily left the EU bloc, which has been reduced to 27 member states.

Brexit supporters gathered in public spaces throughout the country, with crowds cheering in Parliament Square as a simulated Big Ben chimed to mark 11 p.m. The crowd sang the national anthem after marking the moment.

Prime Minister Boris Johnson, one of the most visible and influential "leave" supporters during the June 2016 referendum, issued a national pre-recorded video message an hour before the exit is official. His Cabinet was scheduled to meet Friday in the northern city of Sunderland in a symbolic gesture to honor the occasion -- as the city was the first to call for leaving the union after the polls closed in 2016.

He praised Brexit as a moment of "national renewal."

"In our diplomacy, in our fight against climate change, in our campaigns for human rights or female education or free trade we will rediscover muscles that we have not used for decades. The power of independent thought and action," Johnson said.

Friday began an 11-month transition period during which Britain will practically remain an EU member in everything but name. During that time, Johnson's government will form a new EU relationship covering trade, immigration and other key matters.

Friday night, Britons will no longer officially be EU citizens, but they will have the same membership rights for a year through the transitional period.

Many ardent Brexit supporters were cautious about displaying triumphalism Friday, and instead focused on the future.

EU leaders marked Britain's final day Friday with mixed feelings -- wishing the nation luck but warning of potential trouble at the negotiating table if London insists on departing from EU standards.

"We want to have the best possible relationship with the United Kingdom but it will never be as good as membership," European Commission President Ursula von der Leyen told reporters in Brussels.

U.S. Secretary of State Mike Pompeo promised the United States wishes to maintain a positive relationship with Britain.

"I am pleased the U.K. and EU have agreed on a Brexit deal that honors the will of the British people," he said. "We will continue building upon our strong, productive and prosperous relationship with the U.K. as they enter this next chapter."