She was responding to an op-ed by British Brexit Minister Stephen Barclay, who said the EU's chief Brexit negotiator, Michel Barnier, must go back to EU leaders to change the terms of the talks because the British parliament will not accept the current deal.

"So far it...remains unchanged - this position that the withdrawal agreement is not up for negotiation but we are open to talk about the political declaration," Mina Andreeva told a news briefing in Brussels.

"And of course we are willing to talk and engage with Prime Minister Johnson."

Writing in the Mail on Sunday newspaper, Barclay said the "political realities" had changed since Barnier's instructions were set after Britain voted to leave the EU more than three years ago and that his mandate should reflect those differences.

Johnson has insisted Britain will leave the EU on Oct. 31 with or without a deal, and has told the bloc there is no point in new talks unless negotiators are willing to drop the so-called Northern Irish backstop agreed with his predecessor, Theresa May.

But Barnier has said the EU will not renegotiate the divorce deal, or Withdrawal Agreement, including the backstop, an insurance policy to prevent a return to a hard border between the British province of Northern Ireland and EU member Ireland.

"We are not in the blame game, this is not our business. Our business is to prepare for a no deal," Andreeva said, saying that if Britain left without a deal it would cause "significant disruption" for citizens and businesses and have "a serious economic impact".

"Both sides negotiated with the very best intentions and the very best efforts. The outcome on the table is the best deal possible and I don't think that there is any fault or blame to be looked for in this," she said.

"We just simply expect the UK to live up to its commitment to avoiding a hard border while protecting Ireland's place in the internal market."