Raven said he believed other tombs from the New Kingdom, similar to the one unveiled Tuesday, had yet to be uncovered in Saqqara, which is famous for Old Kingdom antiquities.
Many of the New Kingdom tombs, which date back from 1570 B.C. to 1070 B.C., can be found in the southern Egyptian city of Luxor.
"We hope one day this area will be open to visitors so people can see that Saqqara is not only Old Kingdom but New Kingdom as well," Raven said.
Hawass also unveiled two wooden coffins, 4,000 years old, that were found south of the Step Pyramid. The coffins, painted light orange with blue hieroglyphics, contained human-shaped coffins known as anthropoids, in which lay the mummies of a priest and his girlfriend, Hawass said.
The ancient Egyptians believed anthropoids acted as a substitute body for the dead.
Although archaeologists have been exploring Egypt intensively for more than 150 years, Hawass believes only 30 percent of what lies under the sands at Saqqara has been uncovered.
Saqqara, about 12 miles south of Cairo, hosts a collection of temples, tombs and funerary complexes. Its Step Pyramid is the forerunner of the more sophisticated pyramids in Giza, which are believed to have been built about a century later.
