Another alleged member of the cross-border extremis network, Oussama Atar, is thought to have died in Syria since the Paris and Brussels attacks and could be judged in absentia.
Under the EU deal, musicians are not covered by exemptions allowing for free passage of short-term business visitors, sparking warnings that continental tours by UK bands will become unviable.
"Yet another decline for UK car production is of course concerning, but not nearly as concerning as the New Year nightmare facing the automotive industry if we do not get a Brexit deal that works for the sector," SMMT Chief Executive Mike Hawes said.
Several EU member states have imposed flight, train and ferry bans on UK arrivals since Britain announced the discovery of a new strain of coronavirus.
Johnson and von der Leyen are pressing to break a logjam over fishing rights with just nine days to go before Britain leaves the EU single market and customs union.
"The prime minister will leave no stone unturned in this process, but he is absolutely clear: any agreement must be fair and respect the fundamental position that the UK will be a sovereign nation in three weeks' time," the source said.
Leaders were looking to salvage the EU's 1.8-trillion-euro ($2.1-trillion) budget and coronavirus recovery package, seen as vital for the continent's battered economies, after it was blocked by Hungary and Poland over provisions linking it to the respect for rule of law.
"The chosen measures will be sanctions on individuals, and supplementary measures could be decided if Turkey pursues its actions," a diplomat told AFP.
The EU and Britain had cast Thursday's meeting as a chance to break an impasse in negotiations but both acknowledged there was a danger that a trade deal would elude them.