United Nations chief Antonio Guterres sent a letter Tuesday to Israeli Prime Minister Benjamin Netanyahu protesting a new law that could effectively cripple the UN agency responsible for aiding Palestinian refugees (UNRWA), his spokesman said.

Guterres outlined in his letter "the issues of international law that have been raised by this law," Stephane Dujarric said, adding that it would have a "devastating impact on the humanitarian situation of Palestinians in the occupied territory" if implemented.