Brigadier General Patrick Ryder, the US Department of Defence press secretary, said they had discussed the “ongoing support to Ukraine by our two nations, as well as the continued importance of transatlantic and regional security cooperation in light of Russia’s attack in Ukraine”.
Tuesday’s summit was described by one source as a “planning meeting” as they prepared to respond to Russian aggression.
Austin is understood to have requested the pair meet in person following a bilateral meeting at a Nato conference in Brussels last week.
At the conference, it was announced that the West would send more rockets and drones to Ukraine in response to a run of attacks by Russia on Kyiv using missiles and kamikaze drones.
State-of-the-art advanced medium-range air-to-air missile rockets pledged by Mr Wallace last week can knock cruise missiles out of the sky, while a fleet of drones will be used by Ukraine to gather intelligence from the sky.
Jens Stoltenberg, the Nato Secretary General, said on Tuesday that deliveries of the new air defence systems would begin in the coming days to counter the threat of drones, including the Shahed-136 type supplied by Iran.
Since the summit, Ukraine has said Russian drone attacks have destroyed almost a third of its power stations, which came in response to a string of setbacks for the Kremlin on the front line in Crimea.
A defence source said the Defence Secretary and his US counterpart’s meeting was held to discuss “shared security concerns, including Ukraine”.
It was speculated by another source close to discussions that the meeting had been held in person because of concerns about the security of communications between the Pentagon and Ministry of Defence.
But the source also conceded a physical visit would emphasise friendly relations between Britain and America to foreign observers.
“It’s a good reminder that ultimately the US’s closest security partner is the UK,” they said. “The close cooperation we see on Ukraine is why this relationship is so strong.”
Liz Truss has also spoken to Emmanuel Macron, the French President, about what a Downing Street spokesman described as the leaders’ “deep concern at Russia’s recent barbaric attacks on civilian areas in Ukraine”.
‘West no longer controls the skies in combat’
It comes as Major General James Martin, the Commander of Britain’s Warfighting Division, warned that the proliferation of drones means the West no longer controls the skies in combat.
Major General Martin spoke to The Telegraph in Sennelager, Germany, ahead of Exercise Cerberus, the field Army’s biggest wargaming exercise to take place in Europe in over a decade.
“We don’t assume we have control of air space anymore,” he said.
“We don’t assume we have air superiority or supremacy as we have done in the Middle East. We now assume that we will have limited windows of opportunities to do what we want to do. That’s the difference between fighting a peer adversary vs fighting a counter insurgency.”
Martin added that the “proliferation” of drones in modern warfare “has almost democratised use of the air and aerial surveillance”, because they are so cheap and readily available.
Asked if the exercise was sending a message to Russia, Martin said: “We are absolutely demonstrating to our opponents and our allies and partners that we are ready to fight.
“To the former that we have both the will and capability to fight and to the latter that we are committed and in solidarity with them.
“On both those counts we take this trip deadly seriously. I think a demonstrable UK will to use military force on the continent of Europe is one of the critical outputs of Exercise Cerberus.”