"Secretary Rice told me, she promised me, that she is going to start looking at it," Ismail told reporters at the State Department.
State Department officials were not available for comment. Rice did not speak to reporters.
Ismail's visit to the State Department prompted concern among some lawmakers because of Khartoum's role in the violence in the Darfur region that President George W. Bush's administration has called genocide.
The sanctions against Sudan has been in place since 1993 when it was put on the State Department list of states that sponsor terrorism.
Ismail's visit comes several months after the trip by Sudanese intelligence chief Salah Abdallah Gosh, who was invited by the CIA to share information about the war on terrorism, according to news reports.
The visit sparked outrage because of the violence in Darfur, with lawmakers saying Washington was letting Sudan's strategic role in the war on terrorism overshadow the need to confront the genocide.
The conflict is believed to have left between 180,000 and 300,000 people dead and displaced some 2.4 million from their homes, with 200,000 fleeing into neighbouring Chad.
A ceasefire, concluded in April last year, has never been respected.
Deputy Secretary of State Robert Zoellick, who has made two visits to Sudan in recent months and who met Ismail on Thursday, talked about the possibility of his going to Khartoum for the July 9 inauguration of the Government of National Unity.