Germany, France, the European Union, the North Atlantic Treaty Organization (NATO) and Turkey have voiced support for Britain remaining in the EU ahead of the June 23 referendum on the UK’s membership of the 28-nation bloc.
Speaking after talks with visiting Polish Prime Minister Beata Szydlo in Berlin on Wednesday, German Chancellor Angela Merkel expressed hope that voters will opt for Britain to stay in the EU.
"Of course I want Britain to stay in the EU but the decision is with British citizens," Merkel said.
Meanwhile, French President Francois Hollande stressed that it would be an “irreversible” decision if Britons voted to leave the bloc.
Hollande told a joint news conference with visiting Slovakian Prime Minister Robert Fico in Paris on Wednesday that the Brexit would "necessarily have extremely serious consequences” and would put the UK at "very serious risk" of losing access to the EU's single market.
"It's more than the future of the United Kingdom that is at stake, it's the future of the European Union," he said.
In another development on Wednesday, the president of the European Commission, the executive branch of the EU, emphasized that there would be no changes to a package of measures that EU governments agreed with Britain in February aimed at keeping London in the bloc.
"The British policy makers and the British voters have to know that there will be no kind of any renegotiation. … Out is out," Jean-Claude Juncker said after talks with Austrian Chancellor Christian Kern in the Belgian capital, Brussels.
British Prime Minister David Cameron, who is leading the battle to keep the country in the EU, had suggested that he might push for further EU reforms if the UK votes to stay in the bloc.
Turkish Foreign Minister Mevlut Cavusoglu also told reporters in Ankara that his country strongly backs Britain staying in the European Union.
"We desire Britain to stay in the EU," Cavusoglu said, adding, "Britain's exit would certainly have a negative impact."
The top Turkish diplomat also warned that the EU would weaken if it failed to "renew itself, correct wrong policies and produce solutions to problems faced by European people ... and stand strong against negative trends like racism and xenophobia.”
Also on Wednesday, NATO Secretary General Jens Stoltenberg said that Britain remaining in the EU is key to maintaining security.
"We need a strong Europe and a strong NATO together” to address challenges, he said, noting that “the UK is key in making sure that that happens.”
The NATO chief also warned that “a more fragmented Europe will be something which will only add to the uncertainty which surrounds us."
The remarks came one day ahead of a referendum on whether the UK will remain a member of the EU or not.
British Eurosceptics believe that the country would be better off outside the politico-economic union, but pro-Europeans warn that the move would hurt the economy.