The UN's organisation for helping Palestinian refugees says it needs $1.6 billion to keep running this year after a difficult 2022 during which it took on debt.
"We were barely able to finish the year and keep all our schools and health centres open and running," said Tamara Al Rifai, spokeswoman for the UN Relief and Works Agency for Palestine Refugees in the Near East (UNRWA).
The agency's budget was also $1.6 billion last year, when it took on more than $70 million in debt and liabilities to keep paying salaries for teachers, doctors and other staff numbering 30,000, she said.
"This is not sustainable and not fair for the Palestine refugees who feel the stress of the agency, especially in places like Lebanon, Gaza and Syria," Ms Al Rifai said.
Chronic funding difficulties have been compounded by rising inflation and the priority given by donors to the Ukraine war, she said.
With headquarters in Amman and Gaza, UNRWA has traditionally relied on funding from western donor countries, mainly the US.
A statement from UNRWA chief Philippe Lazzarini said the financial and political circumstances under which the agency was operating had become "incredibly difficult".
He cited a recent visit to Syria, where he saw "indescribable suffering and despair" among Palestinian refugees.
He said their situation was "sadly mirrored in other places like Lebanon and Gaza where Palestine refugees are hitting rock bottom".
Mr Lazzarini called for a "predictable, long-term and regular" way to secure UNRWA funding, as opposed to ad hoc contributions.
"Without it, we will simply not be able to deliver — and with that the lives of Palestine refugees will hang by a thread and millions of people in the region and beyond will be impacted,” he said.
The US was in 1949 instrumental in founding the organisation to which donates $340 million a year, making it the agency's largest contributor. In 2021, the US restored UNRWA funding after it was severed under the Donald Trump administration.
"We cannot and should not be always scrambling to bring in funds to cover our contribution to human rights and stability," Mr Lazzarini said.
“UNRWA has been delivering and responding to the needs of Palestine refugees against all odds, shouldering a huge responsibility until a just and lasting political solution is found."
The agency manages more than 700 schools for half a million mostly Palestinian girls and boys in the Levant. It also provides health care for two million Palestinians, as well giving social assistance to the poorest of them.
Jordan has also called on international powers to increase support for UNRWA.
Its official news agency Petra said Foreign Minister Ayman Safadi and Mr Lazzarini last week discussed a "means of addressing the challenges facing the agency".
It quoted Mr Safadi as saying Jordan was "continuing to work and co-ordinate with international partners to mobilise support for UNRWA" and that the agency was vital for 5.7 million Palestinian refugees in the Levant.
Mr Safadi "stressed the need to diversify funding sources for the agency and ensure financing sustainability", Petra reported.
The operations of UNRWA, the minister said, enhance "regional security and stability".