European Commission vice-president Maros Sefcovic urged Britain on Sunday to make a "big move" to break months of deadlock over post-Brexit arrangements in Northern Ireland that has threatened a trade war.
Sefcovic is set to meet UK Brexit minister David Frost in London on Friday for further negotiations, after talks broke up Friday with Britain saying there was "potential for momentum".
But the UK has hinted it may still trigger a suspension clause in the so-called Northern Ireland protocol, which could spark a damaging trade war and dramatic unravelling in post-Brexit relations.
Brussels has repeatedly warned of "serious consequences" from such a move, suggesting the separate Brexit trade and cooperation deal could be pulled and tariffs imposed.
Months of talks, proposals and counter-proposals have failed to break the impasse, with Britain demanding the protocol is overhauled while the EU has insisted more modest changes offered in the summer can suffice.
"I hope that (the) UK will also now make the big move towards us because we really made far reaching proposals and put them on the table," Sefcovic told the BBC.
"I'm sure that if Lord Frost and (the) UK would double their efforts and come to meet (us) halfway, we can resolve all the outstanding issues to the satisfaction of the people of Northern Ireland."
- 'Fix the problem' -
Agreeing trading arrangements in Northern Ireland, which endured three decades of violence over British rule before a landmark peace deal in 1998, has proved thorny throughout the Brexit process.
The protocol mandates checks on goods heading into the UK province from mainland Great Britain -- England, Scotland and Wales -- at the internal Irish Sea border.
It was designed to prevent checks on goods heading into the European single market at the border with EU member Ireland, as an open frontier there was a key part of the 1998 peace agreement.
The UK says the protocol is unworkable, while there has been unrest from hardline unionists in Northern Ireland who say it cuts them off from the rest of Britain.
The EU has offered to cut checks on a range of goods heading to Northern Ireland but draws the line at a UK proposal to scrap European judicial oversight on disputes.
Writing in the Mail on Sunday newspaper, Frost said the current problems with the protocol "go to the heart of our territorial integrity, of what it means to be one country and one market".
"I still hope the EU can show the ambition needed to fix the problem by agreement," he added.
"If they can't, of course we will have to safeguard our position in other ways."