He said the Cabinet should have a dedicated aid minister, who would be “100% dedicated” to the role.
Chancellor Rishi Sunak has promised to return the UK’s aid contributions to 0.7% by the end of this Parliament.
But Mr Cameron said: “Let’s do more on humanitarian aid. We achieved 0.7% of GDP in our aid payments. I’m sad we’ve got away from that. I hope we can get back there.
“Let’s – with the EU – lead the donor conference, lead the aid effort.
“Let’s have a dedicated aid minister in the Cabinet doing development. The Foreign Office ministers do a great job but it’d be good to have someone who’s 100% dedicated to humanitarian aid and development.”
He also said permanent Nato bases should be created in Estonia, Latvia and Lithuania.
Asked whether he had any regrets about his own time in office and the relationship he had with Moscow, Mr Cameron condemned the “feeble” Western response to Russia’s invasion of Georgia in 2008, and insisted by the time he was in No 10 and Moscow invaded Crimea in 2014 the response was stronger.
But he said there had been “a sense that, look, you had to try and find a way of working with these people”.
Asked about a speech he gave at the State University of Moscow in 2011 where he said Britain and Russia would be “stronger together”, he said: “What I regret is in 2008, when I was leader of the opposition, when Russia effectively invaded Georgia, I went to Tbilisi to show solidarity with President Saakashvili. And if you look at the Western response to Georgia, it was feeble, there weren’t sanctions, there wasn’t pressure put in place.
“We should have done that in 2008 and we did behave differently in 2012 when Putin invaded Crimea, in 2014.”
He said by 2014 the UK was leading the effort on sanctions, adding: “When I think back to that time, you know, we were trying to persuade… I mean, the French at that stage were selling warships to the Russians.”
But he said when he entered No 10 “there was a sense that, look, you had to try and find a way of working with these people”.
“We had to work together over terrorism, we had to work together over climate change. We had to work together over banking regulations,” he said.
“I thought we had to do business with Russia and its leadership, which at that time was more (Dmitry) Medvedev than Putin.”
He rejected any suggestion that Russian money in London or donations to the Conservative Party from Russian donors had influenced policy.
“If the argument is that somehow Russian investment in Britain, or very small numbers of Russians supporting the Conservative Party, somehow changed our policy, I would say that it’s complete nonsense,” he said.
Mr Cameron refused to be drawn on accusations against Boris Johnson regarding the elevation of Evgeny Lebedev to the House of Lords.
Mr Cameron said: “Look, that’s for the Prime Minister to explain and to defend.
“The Lords Appointments Commission is an important body. I always listened to it very carefully. But I’m not here to start throwing bricks at the Prime Minister at this moment.”