UNITED NATIONS (Reuters) - Seven former U.S. ambassadors to the United Nations under both Republican and Democratic presidents urged U.S. Secretary of State Mike Pompeo on Monday to restore U.S. funding for the U.N. agency that helps Palestinian refugees.

U.S. Secretary of State Mike Pompeo speaks during an event to unveil the 2018 Trafficking in Persons (TIP) Report at the State Department in Washington, U.S., June 28, 2018. REUTERS/Yuri Gripas/File Photo

The United States, long the biggest donor to the U.N. Relief and Works Agency (UNRWA), is providing just $60 million of a promised $365 million this year, agency head Pierre Kraehenbuehl told Reuters in April.

U.S. President Donald Trump withheld the aid after questioning its value and saying Washington would only give aid if the Palestinians agreed to renew peace talks with Israel, while the U.S. State Department said the agency needed to make unspecified reforms.

The United States is trying to kick-start stalled peace talks between Israel and the Palestinians, but has not yet revealed a peace plan.

“This financial gap puts into question the ability of UNRWA to continue to deliver education and healthcare services to millions of people, and has national security ramifications for our closest allies, including Israel and Jordan,” the former U.S. Ambassadors to the United Nations wrote in the letter dated July 2.

“We urge you to restore U.S. funding to help fill this gap,” they said in the letter, which was also sent to current U.S. Ambassador to the United Nations Nikki Haley and U.S. National Security Advisor John Bolton.

The letter was signed by Samantha Power, Susan Rice, Bill Richardson and Madeleine Albright, who were appointed by Democratic presidents, and John Negroponte, Edward Perkins and Thomas Pickering, appointed by Republican presidents.

UNRWA was founded in 1949 to aid Palestinian refugees. It serves an estimated 5 million Palestinian refugees in the Israeli-occupied West Bank, in Gaza, Syria, Lebanon and Jordan. It runs some 700 schools, more than 140 health clinics and feeds hundreds of thousands of people.

“Failure to provide desperately needed resources comes with a price. More hardship for communities. More desperation for the region. More instability for our world,” U.N. Secretary-General Antonio Guterres said last week, appealing for UNRWA funding.

“We must do everything possible to ensure that food continues to arrive, that schools remain open and that people do not lose hope,” he said.

More than 130 Palestinians have been killed by Israeli forces in Gaza border protests since March 30. The largest number of deaths occurred on May 14, the day the United States moved its embassy in Israel to Jerusalem from Tel Aviv.

Amid international condemnation of its use of lethal force, Israel said many of the dead were militants and the Israeli army was repelling attacks on the border fence between Israel and Gaza. Washington has maintained Israel’s right to defend itself.

Palestinians and their supporters said most protesters were unarmed civilians and Israel used excessive force against them.