Dan Toole, director of emergency programs for the UNICEF children's agency, said a shortage of donor cash was having a dramatic effect in the territories, which both face international disapproval because of their leaders' policies.
"Isolation, both externally and internally imposed, combined with underfunding for humanitarian aid, is denying children the basic goods and services that would normally be taken for granted," Toole told a Geneva news conference.
"The children of Gaza and Zimbabwe deserve better. They have the right to go to school and be educated, drink clean water and go to bed without being hungry," he said.
Aid funding for UNICEF programs in the whole of the Palestinian territories, including the West Bank as well as Gaza, is running at only 36 percent of needs for this year, while for Zimbabwe it is at 29 pct.
The two areas were typical of UNICEF's "forgotten emergencies" where funds are very short for initiatives to help children, Toole said, describing Iraq, southern Sudan, Chad, Cote d'Ivoire and Pakistan as similarly vulnerable.
Toole said conditions for young people were "nothing short of unbearable" in the Gaza Strip, which was taken over by the Hamas Islamist group last month after bloody clashes with the Fatah movement of Palestinian President Mahmoud Abbas.
The vast majority of all Gazans rely on humanitarian aid, but relief efforts have been largely thwarted by the region's isolation, despite a welcome move by Israel to ease barriers to the delivery of goods, he said.
Price controls recently imposed by the administration of President Robert Mugabe "have resulted in serious shortages of basic goods across the country, including sugar, meat, flour, milk, bread and fuel," hitting children especially hard.
"Malnutrition is growing as parents struggle to feed their families," Toole said.