European leaders have insisted they'll keep working towards an "orderly" Brexit, after British Prime Minister Theresa May announced her departure plans.
She will step down as Conservative leader on June 7th, but will stay on as prime minister until a successor is chosen.
German Chancellor Angela Merkel said she respects the decision, while France's President Macron has called for rapid clarification about what Britain wants.
Mr Macron stressed that "the principles of the EU will continue to apply, with the priority on the smooth functioning of the EU".
The EU's chief Brexit negotiator, Michel Barnier, paid tribute to the outgoing British leader.
Speaking to Sky News in Brussels, he said: "I would like to express my full respect - and if I may my personal respect - to Theresa May, and for her determination in working towards an orderly withdrawal of the UK from the EU.
"I can just add that on our side we will keep working in that direction."
— Michel Barnier (@MichelBarnier) May 24, 2019
Meanwhile, European Commission spokesperson Mina Andreeva said Commission President Jean-Claude Juncker followed Mrs May's announcement this morning 'without personal joy'.
She observed: "The President very much liked and appreciated working with Prime Minister May, and as he has said before Theresa May is a woman of courage for whom he has great respect.
"He will equally respect and establish working relations with any new Prime Minister, whomever they may be – without stopping his conversations with Theresa May."
She stressed that there has been no change in the EU's attitude towards the withdrawal agreement.
Taoiseach Leo Varadkar paid tribute to Theresa May, saying he was sorry to hear of her resignation and she will be missed.
However, he said the change in the British political landscape could be bad news for Ireland.
He suggested: "In the next couple of months we may see the election of Eurosceptic prime minister who wants to repudiate the withdrawal agreement and go for no deal - or we may even see a British government that wants a closer relationship with the EU, and goes for a second referendum.
"Whatever happens, we're going to hold our nerve - we're going to continue to build and strengthen and deepen alliances across the European Union, and we'll make sure that we see Ireland through this."