A "decisive push" is needed to ensure predictability in Northern Ireland, the European Union has urged after talks with Britain in London on how to tweak its post-Brexit arrangements.
Britain has called for changes beyond a package of adjustments set out by the European Commission in recent months that would reduce checks and paperwork on goods flowing from Britain into the North.
Brexit minister David Frost warned that the British government was still prepared to resort to using the contentious Article 16 clause to unilaterally suspend aspects of the Northern Ireland protocol, something the Irish Government has warned would be deeply damaging.
"We would still like to find a negotiated solution. But the gap between our positions is still significant and we are ready to use Article 16 to protect the Belfast Agreement if other solutions cannot be found," Mr Frost said in a statement after meeting European Commission vice-president Maros Sefcovic in London on Friday.
“A decisive push is needed to ensure predictability,” Mr Sefcovic said on Twitter after the meeting with Mr Frost. “We’ll meet again next week.”
The two sides are seeking to break the deadlock over the implementation of the protocol, which covers the special trading arrangements designed to prevent Brexit creating a hard border re-emerging on the island of Ireland.
EU and Irish officials had been concerned that the British government was moving towards triggering Article 16 earlier this month, but momentum appeared to dissipate as the EU warned it would have a severe impact on trade and UK prime minister Boris Johnson faced political trouble at home over a sleaze scandal.
Talks between officials from both sides on technical aspects of customs and other arrangements are due to continue throughout the coming week.
The EU has been keen to nail down a deal covering medicines, but has found agreement from the UK side to be elusive.
There are concerns that time is tight and that a deal on medicines would need to be reached soon in order for the EU to change its laws in time to avoid disruption after the end of this year.
A grace period for border checks and regulatory approvals for medicines is due to expire at the end of December and the EU had proposed adjusting its rules to counter any potential disruption to supply.
But in order to be in place by the end of the year, the EU had hoped to begin its internal approval procedures in the coming week.
Earlier this week, Mr Sefcovic warned that his previously expressed hopes that a deal could be reached before January were “probably too ambitious”.
“I think that if there was the clear political will from the UK side these... problems could be solved,” he told Politico. “But looking at how far we progressed over the last four weeks, the level of detail our UK partners want to discuss, I know that we will probably not be able to resolve everything before the end of the year.”