The US on Thursday pledged more than $1 billion for humanitarian purposes in Syria, Africa’s Sahel region and South Sudan.
This includes more than $720 million for Syria, nearly $152m for the Sahel and almost $108m for South Sudan.
Deputy secretary of state Stephen Biegun announced the Syria aid at a sideline event at 75th UN General Assembly in New York.
Mr Biegun said funds would go to “both for Syrians inside the country and for those in desperate need across the region".
Including this latest aid, the US has supported Syria with more than $12bn since its civil war started in March 2011.
The war started after Syrian President Bashar Al Assad cracked down on anti-government protests, leading to a conflict where Russia and Iran have been supporting the government and the US has backed opposition forces.
Millions are either internally displaced or have fled Syria as refugees.
The fighting continues to be particularly intense in the north-western Idlib province.
The conflict has led to the country’s health infrastructure being woefully under-prepared for the coronavirus pandemic, with a lack of personal protective and medical.
There has also been a steady rise in cases of Covid-19 among UN staff and aid workers in Syria.
"The international community must remain committed to meeting the increasing needs of the Syrian people," Secretary of State Mike Pompeo said.
Mr Pompeo also called for holding the Assad regime "accountable for its devastating military campaign and brutal disregard for human rights, including the arbitrary detention of over 100,000 Syrian civilians, the vast majority of whose whereabouts are currently unknown".
At the same UN event on Thursday, acting USAid administrator John Barsa announced nearly $108m for the humanitarian crisis in South Sudan.
Mr Barsa said the US would also provide $152m in humanitarian assistance for Niger, Mali, Burkina Faso and Mauritania to help them cope with population displacement and food insecurity caused by conflict in the Sahel region.
At the General Assembly on Thursday, African nations called for $300bn in fiscal measures to help economies survive the coronavirus pandemic.
There have been more than 1.4 million confirmed cases on the continent of 1.3 billion people.