The UK could cut its aid to developing countries that fail to invest in their own people, the international development secretary has said.
Penny Mordaunt told the Daily Telegraph she "won't invest" when others should put "their hands in their pockets".
The government is committed to spending 0.7% of national income on overseas aid and currently spends £13bn each year.
Ms Mordaunt said she wanted governments of developing countries to "step up and take responsibility".
"If it chooses not to, that will inform our decisions around our funding," she added.
"We will continue to prioritise investments in saving lives, tackling under-nutrition, improving health and getting kids a quality education.
"But our focus will increasingly be on helping developing countries stand on their own feet and build sustainable health and education systems that they invest in themselves."
Under legislation approved in 2015, the UK government is legally required to spend 0.7% of gross national income on foreign aid.
The UK first met the target on a voluntary basis in 2013, before it was made a legal requirement - although the level of spending has long had its critics in Parliament and the press.
Ms Mordaunt, who replaced Priti Patel as international development secretary in November, backs the 0.7% target but says the public have "legitimate" concerns about the budget.
She said: "What they question is the weight and resource given to this task by their parliament and their government, especially when there are domestic needs and a national debt to address."
Speaking on BBC Radio 4's Today programme, Ms Mordaunt said the UK needs to invest money into "trying to head off problems that will be a difficulty for us in the future", such as pandemics.
She added: "The bar we need to set on aid spending is not just 'are we spending this money well' but could we spend it better in the national interest."
Her comments come two weeks after Foreign Secretary Boris Johnson said the UK's aid budget will be shifted to projects that promote its interests.
He said the money will be "more sensibly distributed" to support foreign policy aims such as denying safe havens to Islamist militants.