Khartoum last week banned the work of at least four humanitarian agencies, including Save the Children.
Salah Barkwayn, a political secretary from the region's Beja Congress Party, was quoted by the independent Sudan Tribune as saying the decision was catastrophic.
"The decision comes at a time when the government is unable to fight poverty and famine from which the people of the east suffer, making them on the verge of famine," he said.
In 2009, Khartoum kicked more than a dozen international aid groups out of Darfur on charges they were spying for the International Criminal Court, which seeks the arrest of Sudanese President Omar al-Bashir.
The aid suspension follows high-level peace talks between officials from Sudan and South Sudan, which gained independence in July under the terms of a peace agreement that ended the Sudanese civil war.
The countries have been on the verge of war since July's independence as ethnic tensions, border skirmishes and disputes over oil threaten the peace.
Eastern Sudan has been at peace or a number of years, though the region is particularly underdeveloped.