A Downing Street spokesperson said: "In separate calls, they agreed that a strong EU was in everyone's interests and that the UK would remain a close and committed ally."
Theresa May called the German Chancellor, the President of the European Council, and the President of the European Commission earlier this evening to update them, ahead of her letter triggering Article 50 and kicking off Brexit negotiations, being delivered tomorrow.
“They also agreed on the importance of entering into negotiations in a constructive and positive spirit, and of ensuring a smooth and orderly exit process," Number 10 said. "The Chancellor, the European Council President, and the European Commission President thanked the Prime Minister for her calls."
The cabinet is expected to meet tomorrow morning rather than their usual Tuesday meeting to allow for May's top ministers to discuss the Article 50 notification.
Then it is expected the Prime Minister will face her typical Wednesday grilling in the House of Commons from midday, with May expected to make a statement following Prime Minister's Questions.
Meanwhile, the notification will take place around the same time.
The UK’s ambassador to the EU, Sir Tim Barrow, will hand-deliver the notification letter to the European Council and its President, Donald Tusk.