"If Barclay delivers the detail of what Johnson discussed with Varadkar yesterday, we may go into more intense talks over the weekend", one senior European Union diplomat said.
Education minister Gavin Williamson restated the government's line that Britain would leave the EU on October 31, come what may, telling ITV: "We need to see the European Union shift".
The meeting Friday appears to signify a change of tone in Brexit negotiations which had reached an impasse mainly over the Irish backstop agreement.
After the Irish prime minister (or "taoiseach") Leo Varadkar suggested that a deal could still be done on-time following one-on-one talks with Prime Minister Johnson and a meeting between Barnier and Britain's Brexit Secretary Stephen Barclay, however, the word has gone out that "tunnel" negotiations may (or may not) be on the cards - although few reporters have elaborated on what this actually means. Even if, as United Kingdom officials hope, Brussels shows flexibility on the timeline, they have yet to enter the "diplomatic tunnel" of final text negotiations.
It is still far from clear whether the talks will produce a workable draft text before the key European Union summit starting on October 17.
France's European affairs minister, Amelie de Montchalin, said early Friday that a no-deal Brexit "is probable, at this stage".
The Democratic Unionist Party (DUP), which supports Johnson's minority government, would have an effective veto on post-Brexit customs checks on the Irish border under proposals put forward by Johnson last week.
The European Union said Friday that talks with the U.K.to find an amicable divorce deal were back on track, despite huge challenges and a looming end-of-month deadline for Britain to leave the bloc.
The main stumbling block remains how the U.K.'s only land border, between Britain and Ireland, is dealt with. But Brussels is adamant it will not agree to any plan that undermines the single market - which allows free movement of goods across Europe - or exacerbates tensions on the island of Ireland.
"We will only ever consider supporting arrangements that are in Northern Ireland's long-term economic and constitutional interests".