Update - 2.16pm: British Prime Minister Theresa May has said there are two main issues where the EU and UK remain a “long way apart” in their Brexit negotiations.
Mrs May, speaking inside 10 Downing Street, said: "I have always said that these negotiations would be tough, and they were always bound to be toughest in the final straight.
"While both sides want a deal, we have to face up to the fact that despite the progress we have made there are two big issues where we remain a long way apart."
Mrs May also reaffirmed the British Government's commitment to no hard border on the island of Ireland, saying she would "we will do everything in our power to prevent a return to hard border".
Mrs May said the first issue was Britain's economic relationship with the EU after Brexit.
"Here the EU is still only offering us two options. The first option would involve the UK staying in the European Economic Area and a customs union with the EU.
"In plain English, this would mean we'd still have to abide by all EU rules: uncontrolled immigration from the EU would continue and we couldn't do trade deals we want with other countries.
"That would make a mockery of the referendum we had two years ago."
On the second issue, she said: "We both agree that the Withdrawal Agreement needs to include a backstop to ensure that if there's a delay in implementing our new relationship, there still won't be a hard border between Ireland and Northern Ireland," she said.
"But the EU is proposing to achieve this by effectively keeping Northern Ireland in the customs union.
Mrs May added the negotiations were at an "impasse", saying: "Yesterday, Donald Tusk said our proposals would undermine the single market. He didn't explain how in any detail or make any counter-proposal. So we are at an impasse."
Mrs May warned EU leaders that their approach to negotiations was "not acceptable" and said that the UK now needed clarity on their position.
She said: "At this stage in the negotiations it is not acceptable to simply reject the other side's proposals without a detailed explanation and counter-proposals, so we now need to hear from the EU, what the real issues are and what their alternative is so that we can discuss them, until we do we cannot make progress."
She said the UK has “treated the EU with nothing but respect” and “the UK expects the same”, adding: “A good relationship at the end of this process depends on it”.
The Prime Minister also offered a reassurance to EU citizens living in the UK that regardless of the outcome of negotiations they would be able to remain in the country.
She said: "There are over three million EU citizens living in the UK who will be understandably worried about what the outcome of yesterday's summit means for their future.
"I want to be clear with you that even in the event of no deal your rights will be protected, you are our friends, our neighbours, our colleagues, we want you to stay."
Mrs May concluded her statement by saying: “The EU should be clear, I will not overturn the result of the referendum, nor will I break up my country. We need serious engagement in resolving the two big issues in the negotiations and we stand ready.”
Theresa May is to issue an update on the ongoing Brexit negotiations in the wake of the rejection of her Chequers plans by EU leaders in Salzburg.
The British Prime Minister will make a statement to cameras at 10 Downing Street.
The move comes after European Council President Donald Tusk ripped up Mrs May's blueprint for Brexit on Thursday, saying it risked the integrity of the EU single market and the Northern Ireland border.
The Taoiseach said Ireland is entering a rocky patch in the negotiations.
Leo Varadkar says he believes the Chequers plan can have some input into the talks but there are obvious problems with it.
He says it is not Europe's fault that Theresa May didn’t get a better reception in Salzburg.
"Perhaps a sense was created that Prime Minister May would come away with something more positive than what occurred, but I don't think anyone in the EU or Ireland is to blame for that.
"Ultimately the problems that are being created for Britain and the British government are a consequence of Brexit and nobody in Europe or Ireland are to blame for that."
Key EU leaders including Angela Merkel and Emmanuel Macron also said significant progress was needed by the European Council summit on October 18 if agreement on the UK's withdrawal deal was to be reached.
Mrs May has indicated that she will come forward "shortly" with new proposals on the thorny issue of the Irish border, which has emerged as the main obstacle to progress.