The UK is weighing up whether to attend a new European political “club of nations” next month.
The first meeting of the “European Political Community” is due to be held in Prague in early October.
Downing Street wants to see more detail on the summit before Prime Minister Liz Truss commits to attending it and no final decision has been made.
The European Political Community is an idea championed by the French President Emmanuel Macron.
He proposed it, in May, as a “new space” for co-operation.
Mr Macron suggested the group could discuss security, energy and transport as well as the movement of people, particularly the young.
The broad intention is to establish a forum that goes beyond the immediate 27 EU member states.
Similar ideas have been floated for decades but this is the first big push for such a forum since Brexit.
UK officials are said to be seeking assurances that the meeting will not be too dominated by EU countries or institutions.
Britain would want to see other “big players” from outside the EU in attendance.
All 27 members of the EU are set to be invited as well as the UK, Ukraine, Norway, Switzerland and Turkey.
Six Western Balkans nations are also likely to be invited, along with Iceland, Liechtenstein, Moldova, Georgia, Armenia and Azerbaijan.
Ms Truss is expected to hold talks with President Macron and European Commission President Ursula von der Leyen at the UN General Assembly in New York, within the coming days.
Relations between Brussels and London have been strained by the row about post-Brexit arrangements for Northern Ireland; an issue the pair are expected to discuss. BBC