"It is once again a wake-up call for all of us in the European Union to ask ourselves how we can strengthen our sovereignty, how we can present a united front even on issues relevant to foreign and security policy," Germany's minister for European affairs Michael Roth said, arriving at ministerial talks in Brussels.

The show of solidarity from Germany and the EU's top officials was welcomed by France, which said the breakdown of trust with Washington strengthened the case for Europe to set its own strategic course.

France's minister for European affairs Clement Beaune called the row "a European issue" not simply a French one, and that Paris expected support from EU partners.

"I don't think France is overreacting and I don't think France should overreact. But when a situation is worrying, is serious, I think it's also our responsibility to state it very clearly," he said.

France is furious that the United States, Australia and Britain worked behind its back to negotiate their AUKUS defence pact and replace Canberra's multi-billion-dollar order of French submarines with US ones.

The European Commission said it was considering whether the diplomatic storm would affect a gathering of a new EU-US Trade and Technology Council in Pittsburgh on September 29 to discuss ways to cooperate on trade and regulating big tech.

"We are analysing the impact that the AUKUS announcement would have on this date," European Commission spokesman Eric Mamer said.

France's minister for trade Franck Riester has not yet decided whether on travelling to Pittsburgh, a source close to him told AFP. He was not formally part of the EU negotiating team, which is made up of European Commission officials.

An EU diplomat said France had "floated" the idea of delaying the TTC meeting, though they face opposition from the Baltic republics, which border Russia and set great store in the NATO alliance.

- 'Irritated' France -

The European Commission, which handles trade policy for the EU's 27 member states, already said on Monday it was looking into delaying negotiations with Australia on Canberra's three-year bid to secure an EU trade deal.

Arnoldas Pranckevicius, the Lithuanian deputy minister for European Affairs, told reporters that overcoming the mistrust would be in the interests of both Europe and the US and that his government "would be the last ... standing in defence of transatlantic unity".

Sweden's EU minister Hans Dahlgren also expressed reserve, saying he understood French irritation but his country wanted more detail on what happened over the submarine deal.

"I don't think we should restructure the EU's trade policy because of this," he said.

The creation of an EU-US tech council was agreed at a summit in June. Washington was expected to use it to seek deeper support from the Europeans on curbing the ambitions of emerging superpower China.