Avoiding a hard border between Ireland and Northern Ireland has become one of the biggest obstacles in clinching an agreement to settle Britain's withdrawal from the EU.
"And we are continuing an intensive work programme to engage on all the scenarios set out in the Joint Report".
According to the Telegraph, Mr Robbins was also warned that Brussels needs "full compliance" with European Union rules on goods and agricultural products in the whole of the United Kingdom - not just Northern Ireland - if customs barriers are to be avoided.
An EU source said there would be more talks in the coming weeks and opportunities for the United Kingdom to come back with fresh proposals ahead of June's summit.
"It has been made very clear to British negotiators that by exclusively pursuing technological solutions, they are ignoring the continuing need for physical inspection of food imported into the UK".More news: Bucks 'Frustrated With Jabari Parker's Immaturity'
"The apparent inability to distinguish between customs checks and food safety measures is deeply concerning, and we strongly urge the government to talk to food safety professionals to ensure that our food supply and safety systems are properly prepared for Brexit". "We are confident that in the coming months, if all sides work together productively, we can achieve a solution to the Ireland/Northern Ireland border that works for everyone involved", reports Reuters. "That continues to be our focus".
"The Irish and Brussels in particular - but I think backed, as far as I can see, by Berlin and Paris - have said the only solution to this is the so-called backstop Option C, which is what the Commission put in print and got the toxic reaction both from the DUP and the Prime Minister".
Mrs May could have to keep Britain in the customs union to avoid a hard border with Ireland. That, candidly, from everything I've heard from various places is still viewed as a bit of a fantasy island unicorn model.
That leaves the second option which would allow the United Kingdom to set its own tariffs on trade while avoiding a hard border, and it is proposals on these solutions that are reported to have been roundly dismissed by the European Union this week.
MPs are pushing for a vote in the Commons next week on remaining in some form of customs union after the government was defeated on the issue in the Lords on Wednesday.
According to news reports, European Union negotiators have rejected as unworkable both of Britain's proposals to keep trade frictionless after Brexit, a "customs partnership" and a "streamlined customs arrangement".