Rishi Sunak's two-day visit to Washington will conclude on Thursday with his fourth meeting with President Biden in as many months, with the issues at stake likely to include Ukraine and the regulation of Artificial Intelligence, as Deputy Political Editor Anushka Asthana reports
The prime minister agreed during a visit to Washington that the inquiry was doing "important and necessary work" but said there was "one specific point of disagreement, which is why there's a legal proceeding underway".
The Covid-19 inquiry is being taken to court by the Cabinet Office over its demand to see all the material it has requested from Boris Johnson in an unredacted form.
Inquiry chair Baroness Heather Hallett is specifically asking to see all of Mr Johnson's WhatsApp messages and notebooks but ministers are concerned about irrelevant personal information being shared.
The documents requested by the Covid inquiry include conversations between Mr Johnson, Mr Sunak and other senior figures still in government.
The PM insisted to Deputy Political Editor Anushka Asthana that he does have confidence in the chair, despite taking her to court over her requests for his old boss's documents.
Former justice secretary Robert Buckland said on Tuesday that the government's decision to sue the Covid inquiry made it look as if there was "something to hide".
Responding to that suggestion, Mr Sunak said: "We are cooperating in the spirit of transparency and candour with the inquiry, the government has handed over, I think, over 55,000 documents so far, so I don't think anyone can say that's not happening.
"There is one specific point of disagreement, which is why there's a legal proceeding underway. But more broadly, I think the work of [the] inquiry is important in the sense that we do need to learn."
Asked whether he was cooperating with the inquiry's requests for his own material, the PM said: "I'm cooperating with the inquiry. I'm actually spending quite a lot of my time doing exactly that."
But Mr Sunak said he was unable to comment further due to the forthcoming legal case, which is expected to be heard by the court of appeal on or shortly after June 30.
Mr Johnson has already agreed to directly provide the inquiry with his documents, despite the court battle but the government says the legal action is necessary to protect the personal information of officials and ministers.
Downing Street said the government is "willing to agree another way forward" when asked whether it is committed to going ahead with legal action against the Covid inquiry.
The prime minister also commented on the situation in Ukraine after a huge damn was destroyed, with Kyiv accusing Russian forces of blowing it up.
Rishi Sunak on Ukraine:
Mr Sunak was unable confirm whether Russia was responsible, telling ITV News he "can't say that definitively yet".
He added: "Our security and military services are working for it. But if it is true, if it does prove to be intentional, it will represent a new low.
"It's an appalling barbarism on Russia's part, but it will fit a pattern of behaviour, specifically and deliberately targeting submitted infrastructure."
The prime minister will meet US President Joe Biden on Thursday in the White House and much of their discussions will centre around how to regulate artificial intelligence.
Rishi Sunak on concerns about artificial intelligence
Mr Sunak wants the US and UK to lead the way in creating rules for how AI should be allowed to work.
"My job is to make sure that we as a country are protected, and I'm confident actually that we can put the guardrails in place.
"We've got a strong track record of doing so. outside of the US our country is the leading democratic nation when it comes to the number of AI companies, the number of researchers the quality of our research, the money invested in it. So I think we can do this and we will do it."
Watch the full interview on ITV's Peston programme at 10:45pm on Wednesday evening