May 29, 2017 0311 GMT
"I can confirm President Bashir will go ... to Saudi Arabia," Ibrahim Ghandour told reporters in Geneva, Switzerland.
"We look forward (to) normalization of our relations with the US," he added.
Trump will start his first ever foreign tour as the president of the United States by visiting Saudi Arabia. He is scheduled to arrive in the kingdom on Saturday.
The summit of Arab and Muslim leaders is expected to include top-level talks the next day.
Asked if the Sudanese president is expected to shake hands with Trump, Ghandour said it was impossible to predict, but added that "a handshake doesn't mean a lot if relations are not (good)."
The Hague-based ICC issued an arrest warrant on July 12, 2010 for Bashir over allegations of genocide committed in Darfur conflict. An earlier arrest warrant for the Sudanese leader was issued in March 2009 by the ICC for charges including war crimes and crimes against humanity.
Bashir has strongly denied the allegations against him, dismissing the claims as a Western conspiracy to seize Sudan's oil, gas and other natural resources.
The armed conflict in the Darfur region of Sudan has killed as many as 300,000 people and displaced 2 million, according to the United Nations.