As the press streamed through the door, the Kremlin’s veteran foreign minister offered a steely nod to one cameraman.

Sergei Lavrov was about to kick off four and a half hours of negotiations with his US opposite number, Marco Rubio, in the Kingdom of Saudi Arabia over how to end the war in Ukraine.

It was the first time the Russian tricolour and the star-spangled banner had flanked such high-level talks between the countries for more than four years.

The meeting, in Riyadh, was possible only after the Saudis, “unusually,” as Lt Gen Keith Kellogg, the US president Donald Trump’s peace envoy, had put it, had managed to convince Vladimir Putin to come to the negotiating table.

Having spoken to his Russian counterpart, Mr Trump, as he often does, decided Washington would work on “Trump time”, attempting to advance the talks at breakneck speed.

At their first meeting on Tuesday, Mr Rubio and Lavrov agreed to “lay the groundwork for future co-operation” in re-establishing relations between Washington and Moscow and ending the war in Ukraine.