Aid groups have slammed Australia’s “bizarre” decision not to increase its $23m aid contribution to war-torn Yemen amid revelations a Canberra defence company had received a $36m taxpayer subsidy towards its military exports to Saudi Arabia.

The United Nations is rattling the tin at an international conference in Geneva urging countries to stump up billions to support 24 million Yemenis or 80% of the population in humanitarian need.

Guardian Australia understands the federal government isn’t pledging any extra cash on top of the $23m allocated to Yemen since 2017. Australia’s last contribution was $3m last April.

The Save the Children spokesman Mat Tinkler said Australia should be in a position to do much more.

“This is a tragedy. One child is dying every 10 minutes,” he told Guardian Australia.

Two-thirds of the country is pre-famine amid four years of war and economic collapse.

An estimated 85,000 children aged under five have died from starvation in the past three years.

The Department of Foreign Affairs and Trade had been funding a Save the Children field hospital in the capital Sana’a which had been caring for malnourished newborns and mothers.

“We were very much hoping for additional contributions to continue that work,” Tinkler said.

“It’s at risk. It’s being supported by Save the Children’s own funding at the moment.”

The UN had dubbed the field hospital the “gold standard” and was looking to replicate the model in other parts of Yemen, Tinkler said.

He seized on revelations from last week the federal government had given Canberra-based defence firm Electro Optic Systems $36m in taxpayer subsidies.

The company has contracts to export its remote weapons systems to Saudi Arabia and the United Arab Emirates – both countries are involved in the Yemen conflict.

Save the Children has launched a petition calling on the government to ban Australian arms exports to the countries.

A steady stream of other countries are shunning Saudi Arabia as a military export destination.

A British parliamentary committee report said the UK is on “the wrong side of the law” by sanctioning arms exports to Saudi Arabia and should suspend export licences.

Germany has suspended arms sales to Saudi Arabia, and Italy, Denmark and Finland have announced plans to follow suit. The US Congress has voted to withdraw US support from involvement in Yemen.

Australian defence officials couldn’t guarantee the EOS weapons systems are not being used in the Yemen.