WHO said in a statement on Wednesday that the number of financial approvals in June was 80 percent lower than the monthly average for 2016.
According to WHO figures, only 477 Gazans were given financial approvals to travel for treatment during the month, while a total of 1,883 people had gotten the permission in June last year.
Before seeking Israeli permits, Gazans in need of medical care outside of the coastal enclave must first apply to the Palestinian Authority for permission and financial aid.
The Palestinian Authority has recently been under fire for imposing “punitive measures” against the Gaza Strip to squeeze the Gaza-based Palestinian resistance movement, Hamas.
Among the punitive measures is the reduction of electricity payments to Gaza. Israel has drastically cut its electricity supply to the coastal sliver at the request of the Palestinian Authority.
Health Ministry officials in Gaza have condemned the measures, urging international organizations to pressure the Palestinian Authority to stop the acts.
Gaza has been under an Israeli siege since June 2007. The blockade has caused a decline in living standards as well as unprecedented unemployment, poverty and shortage of advanced medical equipment.
Last month, the UN Humanitarian coordinator for Gaza, Robert Piper, criticized the Palestinian Authority for politicizing medical care.
"The Palestinian Authority has been taking certain measures to at least slow access to proper health care," Piper told AFP, adding, "These sorts of measures for us are not acceptable."