“We express our deepest condolences to the people of Oman,” TASS quoted a statement circulated by the White House press service.
The American leader emphasized that the Sultan brought "peace and prosperity" to his country.
He also noted al-Saeed's efforts to achieve peace in the region.
Earlier, Israeli Prime Minister Benjamin Netanyahu expressed his condolences to the people of Oman on the death of Qaboos bin Saeed Al Saeed.
The Sultan of Oman, who ruled the country since 1970, died at the age of 79.