Australian prime minister Malcolm Turnbull has said he is "confident" that his country's negotiations towards a free trade agreement with the EU will continue.
Former Swedish prime minister Carl Bildt called the result "beyond comprehension" and predicted long-term turmoil as a result of the vote on Twitter. He also noted that the Zimbabwean dollar was gaining on sterling.
Dutch anti-immigration leader Geert Wilders called for a referendum on the Netherlands' membership in the EU following the British result.
"We want be in charge of our own country, our own money, our own borders, and our own immigration policy," he said in a statement.
Manfred Weber, a senior German conservative MEP and a close ally of Angela Merkel, has warned Britain will receive "no special treatment" and must leave the EU within two years.
He writes in four tweets: "We respect and regret the decision of the British voters. It causes major damage to both sides.
"This was a British vote, not a European vote. Co-operation within Europe is a question of self-assertion of the continent.
"We want a better and smarter Europe. We have to convince the people and bring Europe back to them.
"Exit negotiations should be concluded within two years at max. There cannot be any special treatment. Leave means leave."
France's far right National Front party called for a referendum on European Union membership in France on Friday as Britain voted to leave the bloc.
"The liberty of peoples always wins in the end! Bravo to the United Kingdom," said FN deputy leader Florian Philippot on Twitter. "Our turn now #Brexit #Frexit."
The FN has long called for France to exit the EU and has performed well in recent elections, even though it has yet to break through effectively in second-round voting.
The Irish Times reported that Northern Ireland voted to stay in the EU and promptly called the result a "nightmare"
News organisations report
Newspaper readers in the UK readers will wake up this morning to these front pages:
The Daily Telegraph's 5am edition front page displayed this celebratory scene:
The Scottish Daily Mail also produceda 5am special edition, the front page of which read "We're out"
The Daily Mirror described the result as a "shock"
And The Sun proclaimed "See EU later"