UNITED NATIONS, United States (AFP) - British Foreign Secretary Boris Johnson came to the United Nations on Friday (July 22) to deliver the message that Britain's vote to leave the European Union did not signal a turn toward isolationism.

Johnson, who led the Brexit campaign, rejected comparisons between his political views and those of US presidential candidate Donald Trump, who has vowed to put "America first."

"I would draw a very, very strong contrast between Brexit and any kind of isolationism," said the former London mayor who was appointed last week.

"Brexit means us being more outward-looking, more engaged, more enthusiastic and committed on the world stage than ever before," he said.

Johnson met with UN Secretary-General Ban Ki-moon to discuss international efforts to end the wars in Syria, Yemen and Libya, and with the French and US ambassadors.

The foreign secretary said the "mood had changed" in Europe and around the world in the weeks following the shock result of the referendum "as understanding starts to break in".

"People see what this is all about - the opportunities and the positive side of this as well," he said, adding that he was "very, very encouraged" by the talks he had held with foreign diplomats.

Johnson took Britain's seat at the UN Security Council to vote in favour of a British-drafted resolution on ridding Libya of its chemical weapons stockpile.

"I never thought I would do that in my life," he commented.

The foreign secretary said he was "shocked and saddened" by the attack in Munich, adding that if the violence was terrorism-linked "it proves once again that we have a global phenomenon, a global sickness."

Johnson said terrorism and violent extremism must be tackled globally.