"As of right now we don't have a date but we will let you know when we do," Us Weekly magazine quoted him as saying.
The couple had cancelled their wedding on Saturday without any explanation. Several reports and blogs suggested that the cancellation was due to bad blood between Foster and Usher's mother, recent reports about Foster's criminal past, and Foster's resistance to signing a prenuptial agreement.
A source close to the couple has, however, dismissed these rumours as mere speculations.
"People are just hating," says the insider, who reveals the real reason they postponed the wedding was due to a pre-term labour scare.
The source said that the four-months pregnant Foster was admitted to St. Vincent's Medical Center in New York City after suffering cramping, but upon examination "she learned it was just uneasiness brought on by the stress of the wedding."
According to the source, it was at that point that Usher decided to postpone the ceremony.
"Everbody's fine. Tameka and the baby are fine," Usher himself said after the couple arrived via private plane in New York.
"We're good. We're all doing great now," Foster chimed.
Meanwhile, a friend of the couple has said that they love each other very much, and will soon get married.
"There will be a second wedding ceremony. This is just a postponement. They are very much in love," said the source.
Usher and Foster got engaged in January, and they announced the latter's pregnancy at the end of June.
This will be Usher's first child, while Foster has three children from a previous marriage.