European Commission vice-president Maros Sefcovic said there had been a "change in tone" from Brexit minister David Frost in the fourth round of talks held on Friday.
Speaking at a press conference, Mr Sefcovic said: "I acknowledge and welcome the change in tone of discussion with David Frost today, and I hope this will lead to tangible results for the people in Northern Ireland. "
He told reporters the UK needed to "reciprocate the big move the EU has made" on the Northern Ireland Protocol.
Mr Sefcovic said he raised “forcefully” that “serious headway” needs to be made in negotiations next week – stressing the importance of medicines.
He said: “We can and must arrive at the agreed solution that Northern Ireland truly deserves. That is also why I raised forcefully that we need to make serious headway in the course of next week.
“This is particularly important as regards the issue of medicines. An uninterrupted long-term supply of medicines from Great Britain to Northern Ireland is the protocol-related issue on everyone’s mind in Northern Ireland.”
Mr Sefcovic said: “I stand by my commitment to do whatever it takes to address this issue in line with what industry tells us. I prefer to have a joint solution with the UK Government but if we are to amend our own EU legislation – something we are committed to do – we need to find this solution quickly.
“We will therefore intensify our talks next week.”
Earlier Minister of State for European Affairs Thomas Byrne said a "tough guy" approach when it comes to Northern Ireland will lead to disaster.
Mr Byrne was speaking as EU and UK Brexit negotiators prepare to meet in London for talks on breaking the deadlock over the contentious protocol.
He has raised concerns over stability in Northern Ireland, with the UK threatening to trigger Article 16 of the protocol, a move that would suspend parts of the deal that has prevented a hard border on the island of Ireland.
Asked on BBC Radio 4's Today programme if there is a serious danger of a full-scale trade war, Mr Byrne said: "There is a serious danger of complete instability in Northern Ireland and that's what motivates the Irish Government in all of our dealings in relation to the protocol."
He said the countries involved have worked together for decades to ensure stability, saying "we now have a division, it seems, because of threats by the British Government to, what they say, is to suspend the protocol under Article 16. We're not entirely clear what that's about."
Challenged on instability in Northern Ireland and the current arrangements, he said: “I don’t think that the people who are burning buses in Northern Ireland at the moment ... are fully aware of all of the details and the intricacies of the protocol.
“What they need to see, and what people in Northern Ireland need to see, is both governments working together.”
He said the EU has listened to the concerns of Northern Ireland and is in “solutions mode”, adding: “A tough approach, or a tough guy approach, when it comes to Northern Ireland can only be counter-productive and will lead to disaster.”
He said he is “very glad despite that gloomy atmosphere” that there are talks taking place on Friday, adding “there is a prize of stability and peace in Northern Ireland” as well as continuing good diplomatic relations between Britain and the EU.
Mr Byrne said the situation in Northern Ireland “is clearly very fragile”.
He referenced BBC reporting on “instances of violence, instances of fragility of that peace process this week”.
He added: “Further instability will only lead to a continuation of that.
“If we can get certainty, if we can get a continuity in trading arrangements, and less of this discussion, what will happen is that the economy in Northern Ireland will prosper and that then helps as well the social situation, which is very, very delicate at the moment.”
In October, the EU offered a series of changes to the protocol which would remove 80 per cent of checks on goods between Northern Ireland and the UK mainland.
But the UK Government wants further alterations, including removing the role of the judges in the European Court of Justice (ECJ) as the arbitrators of disputes.
There is growing speculation that the UK is poised to use a get-out clause from the deal in the coming weeks.
Mr Frost told the House of Lords on Wednesday that triggering Article 16 – which would effectively suspend elements of the arrangements – will be the UK’s only option if the dispute is not resolved.
He there is “a real opportunity to turn away from confrontation, to move beyond our current difficulties and put in place a new, and better, equilibrium” in the talks.
But he added it is “not inevitable” that Article 16 will be triggered.
He said: “In my view, this talks process has not reached its end.
“Although we have been talking nearly four weeks now, there remain possibilities that the talks have not yet seriously examined, including many approaches suggested by the UK.
“There is more to do and I will certainly not give up on this process unless and until it is abundantly clear that nothing more can be done. We are certainly not there yet.
“If, however, we do in due course reach that point, the Article 16 safeguards will be our only option.”
The Irish Government has held talks with US president Joe Biden’s administration about the protocol.
On Thursday, Minister for Foreign Affairs Simon Coveney said contact with the US government was designed to "encourage progress" in negotiations.
The protocol effectively keeps Northern Ireland inside the EU’s single market for goods, resulting in some checks for products crossing the Irish Sea from Great Britain. – PA