KINSHASA, Zaire: Mobutu Sese Seko's abrupt announcement that he will leave Kinshasa for a Wednesday meeting in Gabon with friend and longtime supporter President Omar Bongo has many wondering if Zaire's ruler of 32 years will ever return. Mobutu aides say he will come home Friday, but with Laurent Kabila reportedly less than 100 miles from Kinshasa, many are speculating that Mobutu will leave Gabon for exile on the French Riviera. One possible indication that Mobutu is ready to relinquish Zaire: The itinerary of U.S. envoy Bill Richardson. After a day of talks with Mobutu representatives, Richardson is headed to Paris where he could be looking for assurances from French officials that should Mobutu come to France, as one of his aides has already suggested, he can retire there unmolested. Although Kabila has indicated he would give Mobutu time to leave the capital, continued sporadic fighting continues to worry U.S. officials. Although Kinshasa remains calm, State Department spokesman John Dinger urged Americans in the city to leave immediately.