Brussels - The European Union lamented the standstill on crucial issues after the latest round of Brexit talks ended on Thursday, with the fate of Northern Ireland's border remaining a major sticking point.

With five weeks to go before an important EU summit in late June, time to make progress in the talks over the terms of Britain's divorce from the EU and future relations might be running out, a senior EU official warned.

"On the basis of this week's discussions, I am a bit concerned," the official said, speaking on the condition of anonymity.

The official noted that Britain was trying to shift the blame for the negative consequences of Brexit to the EU.

"At the moment, I have the impression the UK thinks everything has to change on the EU side, so everything can stay the same for the UK," the official said. How to avoid a hard border between the Republic of Ireland and Northern Ireland is a top concern. Britain said it would make a written proposal on possible solutions within two weeks.

Objection to Britain's participation in the Galileo programme

Britain's ideas presented so far are not acceptable to the bloc, the EU official said, adding that the EU wanted to achieve "substantial progress" on the border issue by the EU summit.

Another issue that has emerged lately is a row over the Galileo satellite programme, with Britain issuing a "strong objection" to its exclusion from the project. The Galileo programme is a flagship EU space strategy initiative, aiming to provide navigation data that offers an alternative to the US-based Global Positioning System, or GPS. It is intended for use by industry and the military, as well as emergency response units.

According to the European Commission, Britain's departure from the EU means it can no longer participate in Galileo - an argument disputed by London. "The UK decided unilaterally and autonomously to withdraw from the EU. This implies leaving its programmes as well," the bloc's Brexit negotiator Michel Barnier said earlier this month, adding that cooperation on Galileo needs to be put on a "new basis."

Under EU rules, "third countries - and their companies - cannot participate in the development of security sensitive matters," Barnier said, while adding that Britain could continue to use Galileo's encrypted signal.

Exclude Britain from security-related discussions

But London argues that its participation is of interest to both sides, while threatening to develop a rival programme if excluded.

The government warned in a paper published Thursday that excluding British industry from Galileo "risks delays of up to three years and additional costs of up to 1 billion euros to the programme."

It also issued a "strong objection" to Britain's exclusion from security-related discussions about the period after Britain leaves the EU in 2019, arguing that this was pre-empting decisions that had not yet been taken on their future security relationship.