Britain has been accused by Save the Children of "exporting fear" to children trapped in Yemen's civil war by selling arms to Saudi Arabia.
The charity said the UK's aid effort in the conflict is undermined by selling weapons to the Arabian kingdom, which is leading a coalition in support of Yemen's internationally recognised government against Iran-backed Houthi rebels.
The report said that while the UK is one of the largest international donors to help those trapped in a war which has killed thousands, Saudi Arabia is killing Yemeni children, bombing schools and hospitals, and impeding aid access.
More than £3.3 billion worth of UK arms sales to Saudi Arabia have been licensed since the bombing began in March 2015.
Since then, more than 4,000 children have been killed or maimed by all sides in the conflict, although the United Nations has identified air strikes by the Saudi-led coalition as the leading cause of child casualties, Save the Children said.
The charity's chief executive Kevin Watkins said: "The UK is leading the world by providing aid to Yemen, but we are also providing weapons and support to countries involved in a conflict that is killing, maiming and starving children.
"The UK should stand tall in the world and export hope to Yemen's children, not fear."
The charity called for the Department for International Development to be given a decision-making role on the Government's export control joint unit, which approves all arms sale licences.
The unit currently includes representatives the Foreign Office, Ministry of Defence and Department for Business, Energy and Industrial Strategy.
Shadow international development secretary Kate Osamor said: "This report sounds the alarm bells once again on the 'disjointed' cross-government approach to international development, and highlights the sheer hypocrisy of delivering aid to Yemen while British-made bombs rain down.
"Labour will review the way that decisions are made on the exports of arms and we will review the cross-government approach to aid spending, making sure it delivers development outcomes for the world's many, not short-term benefits for the few."
A Government spokesman said: "The UK is the third largest donor to Yemen, having committed over £155 million in UK aid this year. We are also playing a leading role in diplomatic efforts to achieve a political solution which can end the conflict and the terrible humanitarian suffering, including building support for the UN Special Envoy's proposals for peace.
"The intervention by the Saudi Arabian-led coalition came at the request of Yemen's internationally-recognised President, whose Government was forced to flee following a violent takeover by the Houthi rebel group.
"Since then rebels have launched missile attacks into Saudi Arabia and committed serious human rights violations. We remain deeply concerned about the human rights situation in Yemen and will continue to work with all parties to find a political solution to the conflict.
"The UK Government takes its defence export responsibilities very seriously and already operates one of the most robust export control regimes in the world. We rigorously examine every application on a case-by-case basis against the consolidated EU and national arms export licensing criteria."