Boris Johnson will start a week of intense diplomacy on Monday, as he tries to push for a Brexit deal on the sidelines of the United Nations General Assembly in New York.

The British prime minister will hold meetings this week with all the key players — Germany's Angela Merkel, French President Emmanuel Macron, Irish Prime Minister Leo Varadkar and European Council President Donald Tusk. He will try to persuade them to renegotiate the divorce deal they agreed to with his predecessor, Theresa May, that was rejected three times by Parliament.

"I would caution you all," he told reporters on the plane to New York, trying to reduce expectations. "I don't wish to escalate excessively the belief that there will be a New York breakthrough. We will be pushing ahead but there is still work to be done."