BRUSSELS -- Britain and the European Union refused to budge an inch Thursday toward any compromise over Brexit, but at least they are on speaking terms again about their impending divorce.
They agreed to further negotiations in the next few weeks, although that means any deal will come perilously close to the scheduled deadline of March 29. That risks a chaotic departure for Britain that could be costly to both sides — both to businesses and ordinary people.
"A no-deal is for us not an option. It is a disaster on both sides of the Channel," said Guy Verhofstadt, the European Parliament's chief Brexit official.
Looking at the ever-tighter deadline, British Prime Minister Theresa May said after talks at EU headquarters in Brussels, "it's not going to be easy."
But she vowed: "I am going to deliver Brexit. I am going to deliver it on time."
May was able to clear the air after EU Council President Donald Tusk exacerbated the frosty climate Wednesday by wondering aloud what "special place in hell" might be reserved for those who backed Brexit with no idea of how to deliver it.
May said she had "raised with President Tusk the language that he used," saying his words "caused widespread dismay" in Britain.
Tusk's comments were condemned by British Brexiteers but at least served to focus minds on how wide a gulf remains between the U.K. and the EU. It was little surprise that talks at EU Commission headquarters were described as "robust."
At the end, May and EU Commission President Jean-Claude Juncker agreed on a renewed effort to hold more negotiations on seeking a breakthrough.
The two leaders agreed to assess progress "before the end of February to take stock of these discussions," a joint statement said. Two years ago, May set Brexit day as March 29 — and original plans were to have a deal in place six months ahead of time.
As the time shrinks between a deal and the cutoff date, the more difficult it becomes for businesses and authorities to adapt quickly to the fundamental changes that a withdrawal from the bloc would entail.
Both sides still disagree on whether the divorce agreement struck between May's government and the EU — and then summarily rejected by Britain's Parliament — can be changed to ease British objections.
"The EU27 will not reopen the Withdrawal Agreement, which represents a carefully balanced compromise between the European Union and the U.K., in which both sides have made significant concessions," the joint statement said.
U.K. officials said May's primary concern was not to be "trapped" in a system that could see Britain linked to the EU in a customs union for an indefinite time and not be able to set its own trade agenda.
Britain's Parliament voted down May's Brexit deal last month, largely because of concerns about a provision for the border between the U.K.'s Northern Ireland and EU member Ireland. The mechanism, known as the backstop, is a safeguard that would keep the U.K. in a customs union with the EU to remove the need for checks along the Irish border until a permanent new trading relationship is in place.
Thursday's statement said that May "raised various options for dealing with these concerns in the context of the withdrawal agreement."
Many pro-Brexit lawmakers in Britain say they won't vote for the withdrawal agreement unless the backstop is removed from the 585-page, which the EU leaders oppose vehemently.
Juncker and the other leaders have agreed to look for a compromise in a political text accompanying the withdrawal agreement, but not in the document itself.
"What we would look at as positive from today is that there are going to be talks," a senior Downing Street official said, speaking on condition of anonymity to discuss the UK-EU negotiations. "Obviously we've got work to do."
In London, there was significant momentum from the opposition, with the Labour Party making perhaps its biggest move in months.
Party leader Jeremy Corbyn dangled a possible way out of the impasse, saying his left-wing party could support a Brexit deal if May committed to seeking a close relationship with the EU after Britain leaves. That would include a commitment to maintain roughly equivalent standards in areas such as the environment and workers' rights.
Corbyn's key demand, set out in a letter to May, is permanent British membership in a customs union with the EU. May has repeatedly ruled that out, but it would solve the problem of the backstop by making customs checks on the Irish border unnecessary.
It is the firmest sign yet that Labour lawmakers might be willing to vote for a Brexit deal in Parliament. But the party — like May's Conservatives — is divided. Corbyn's position disappointed some Labour Party legislators who had hoped he would back calls for a second referendum on whether to leave the EU.
Britain's Parliament is set to hold a debate and votes Feb. 14 on the next steps, giving lawmakers a chance to force May to change course toward a softer Brexit — if divided lawmakers can agree on a plan.
Corbyn said Thursday that Labour would "do everything we can in Parliament to prevent this cliff-edge exit."
"Half of our trade is with Europe. A lot of our manufacturing industries are very frightened, very worried," he said.
Lawless reported from London.