International NGOs have condemned the US government's decision to cut more than half of its planned funding to the United Nations agency for Palestinian refugees.

Kenneth Roth, executive director of Human Rights Watch, said in a Twitter post late on Tuesday that Washington was "holding Palestinian kids' humanitarian needs hostage to political agendas".

Jan Egeland, secretary-general of the Norwegian Refugee Council, urged the US government to reverse its decision announced on Tuesday to withhold $65m out of $125m aid package earmarked for the United Nations Relief and Works Agency for Palestinian Refugees (UNRWA).

"The move will have devastating consequences for vulnerable Palestinian refugees across the Middle East, including hundreds of thousands of refugee children in the West Bank and Gaza, Lebanon, Jordan and Syria who depend on the agency for their education," he said in a statement on Tuesday.

"It will also deny their parents a social safety net that helps them to survive, and undermine the UN agency's ability to respond in the event of another flare-up in the [Israeli-Palestinian] conflict."

Cutting aid to innocent refugee children due to political disagreements among well-fed grown men and women is a really bad politization of humanitarian aid. Jan Egeland - Norwegian Refugee Council

On Twitter, Egeland said: "Cutting aid to innocent refugee children due to political disagreements among well-fed grown men and women is a really bad politization of humanitarian aid. US holds back $65m aid to Palestinians."

The Turkish Mnistry of Foreign Affairs said cuts to UNRWA would "hamper the efforts towards a two-state political solution and regional stability". It also said that Ankara would increase its contributions to the agency.

Yazan Muhammad Sabri, an 18-year-old Palestinian refugee in Dheisheh camp in the occupied West Bank town of Bethlehem, told Al Jazeera last week that "if the wakala [UNRWA] goes away, there will be no education, no healthcare, no sanitation".

"There will be nothing - everything will disappear," he said.

Salah Ajarmeh, a 44-year-old refugee living in West Bank's Aida camp, told Al Jazeera that "if the services stop, there will be a revolution".

"Palestinian uprisings began in the refugee camps in Jordan and Syria, and this will happen again."

'Not a bargaining chip'

Husam Zomlot, head of the Palestine Liberation Organisation's delegation to the US, said in a statement on Wednesday that Palestinian refugees and children's access to basic humanitarian services was "not a bargaining chip but a US and international obligation".

"Taking away food and education from vulnerable refugees does not bring a lasting and comprehensive peace," the statement said.

"Heeding Israeli Prime Minister [Benjamin] Netanyahu's zero-sum game to take Jerusalem off the table and now attempting to dismantle UNRWA, thinking that it would relinquish the rights of Palestinian refugees is a fallacy."

Zomlot was referring to the earlier US decision to recognise Jerusalem as Israel's capital, a move that prompted widespread international condemnation and led Palestinian leaders to say that they would "no longer" accept any peace plan put forward by the US.

Tuesday's announcement on UNRWA came after US President Donald Trump had threatened on January 2 to cut aid to Palestinians.

In a series of tweets, Trump had said: "... We pay the Palestinians HUNDRED OF MILLIONS OF DOLLARS a year and get no appreciation or respect.

"... With the Palestinians no longer willing to talk peace, why should we make any of these massive future payments to them?"