Javed Nawaz said he agreed to make a one-day round-trip from Chicago to Washington last March because of a sense of obligation to a fellow Pakistani. He said he went to the L'Enfant Plaza Hotel to pick up the friend's "property" but never asked what it was.

"It is a tradition in my country that everybody minds his own business," Nawaz told a jury here yesterday in U.S. District Court, where he is on trial on charges of attempting to possess heroin with intent to distribute it. "We don't go into personal things."

If he had known he was making the trip to pick up drugs, "I would never have come," said Nawaz, 30, who said he is an illegal alien and has operated sandwich shops around Chicago for the last four years. "Obligation applies to me, but that doesn't mean I should do a criminal act . . . . I cannot jeopardize my respect and my dignity for criminal activity . . . . "

Nawaz was arrested in the hotel March 27 after carefully placing five packages of white powder in a suitcase. He acknowledged that when he received the packages from another Pakistani he thought they were heroin, but didn't refuse them because "I was scared for my life."

Actually, according to prosecution witnesses earlier, the five one-kilogram packages contained flour and sugar that had been substituted for heroin by the Drug Enforcement Administration.

Moazzam Khan, a Pakistani prosecutor, testified that he had obtained heroin worth $20 million in Pakistan, and then assumed the role of a courier in an elaborate "sting" operation arranged by the DEA. His delivery to Nawaz was recorded by the DEA on videotape and shown in court.

Nawaz confirmed Khan's testimony that he had identified himself through code words and the serial numbers on Pakistani currency as the person to whom the delivery would be made. But he said he had been given the words and the numbers by a friend, whom investigators have been unable to locate, prosecutors said.

"I felt I had just come to pick up somebody's property . . . , " Nawaz said. "I didn't know it was drugs."

He said another friend had traveled with him and had provided the suitcase. Assistant U.S. Attorney Barry Tapp said this man was not charged.