US President Joe Biden admitted to his French counterpart Emmanuel Macron Friday that his country had been "clumsy" by securing a submarines deal with Australia behind France's back.
"We have no better ally than France," Biden said in the first meeting with Macron since the row erupted last month.
"What happened was, to use an English phrase, what we did was clumsy, it was not done with a lot of grace," added Biden, who travelled to Rome to attend a weekend G20 summit.
It was the clearest sign of contrition from the US since the start of a diplomatic row that saw France recall its ambassadors from Washington and Canberra.
"I was under the impression that France had been informed long before, that the (French) deal was not going through," the US president said.
Biden called France an "extremely, extremely valued partner... and a power in itself" with the "same values" as the United States.
Macron welcomed the efforts put in place by the US to defuse the crisis, noting that a series of consultations between Paris and Washington had taken place in recent weeks.
"We clarified what we need to clarify," said Macron.
"What really matters now is what we will do together in the coming weeks, the coming months, the coming years," he added.
France expects more US support for its military mission against jihadists in the Sahel, as well as clearer support for plans to beef up European defence capabilities.
Strengthening EU defence has long been a French objective, but it has traditionally been viewed with suspicion in Washington due to the risk of undercutting the US-led NATO alliance.
But in another Rome meeting with Italian Prime Minister Mario Draghi, the G20 summit host, the US president seemed open to the idea.
Biden and Draghi spoke of "the usefulness of developing a European defence also with regard to transatlantic security, in full complementarity," the Italian government said.
The Franco-American row erupted last month after Australia walked out of a multibillion-dollar submarines deal with Paris in favour of an alternative one with the US and Britain.
An enraged French government called the deal, which led to the cancellation of a contract with Australia worth more than 50 billion euros ($57.7 billion), "a stab in the back".
Australia announced the pact as it joined a new defence alliance with Britain and the US dubbed AUKUS, one of a series of initiatives by Biden who views countering China as the paramount concern of the United States.