Foreign Minister Julie Bishop has defended Australia’s promise of $A20 million to assist Syrian refugees after other nations at a Syria donors’ conference in London promised vastly bigger sums.

The sum was dwarfed by the pledges of Britain, which promised $A2.44 billion by 2020, Germany ($A3.6 billion by 2018), the United States ($A1.3 billion immediately), Norway ($A1.62 billion by 2019) and Italy ($A555 million by 2018).

Labor criticised Australia’s funding pledge as “extraordinarily low” while an aid group called it a “drop in the bucket”.

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At least 10,000 civilians have died and many more displaced by the civil war. Photo: Getty

Ms Bishop defended the pledge by saying the Australian government had been contributing since 2011, it was already funding an expensive military campaign against the Islamic State (IS) terrorist group, and that it did not have “a bottomless pit” of funds.

“A number of countries are making a pledge for the very first time. Australia has been contributing from the outset,” she told reporters on Friday (AEDT).

The total value of Australia’s contributions to the conflicts in Syria and Iraq to date total $A1.5 billion, the minister claimed, which would put it among the highest contributors.

Australia will spend $A400 million on the fight against IS this financial year, and a further $A830 million to settle 12,000 Syrian refugees over four years, Ms Bishop said.

“That was a significant contribution by any measure.”

Ms Bishop said Australia was also looking at an assistance package to help Jordan and Lebanon cope with the burden of the many Syrian refugees they hosted, and that would involve further funding.

She denied that was a late addition to Australia’s commitment at the conference prompted by potential embarrassment on the world stage over its funding pledge.

Ms Bishop defended the comparatively small pledge by pointing to previous contributions. Photo: AAP

She said aid groups who criticised the funding pledge should say “where they would like me to cut funding in order to provide more”.

“This is not a bottomless pit.”

Opposition foreign affairs spokeswoman Tanya Plibersek criticised the $A20 million pledge as “extraordinarily low” and suggested the government should scrap a “dumb plebiscite” on same-sex marriage and divert the $A160 million in savings to Syria instead.

CARE Australia CEO Julia Newton-Howes described the pledge as a “drop in the bucket”.

-with AAP