An attorney for the Americans asked for more time to review the case, CNN said.
Only 14 of the 43 defendants appeared in the metal defendants cage at the start of the trial Sunday afternoon in suburban Cairo, The New York Times reported. The defendants are charged with operating unlicensed nonprofit groups in Egypt and receiving money from abroad under the names of their employees instead of official bank accounts.
Seven of the American defendants remain in Egypt, including Sam LaHood, the son of U.S. Transportation Secretary Ray LaHood. They have taken refuge in the U.S. Embassy.
The seven Americans work for the International Republican Institute and the National Democratic Institute, which work to promote democracy abroad. Prosecutors allege the groups worked with U.S. intelligence officials in a campaign to destabilize Egypt.
The defendants face up to six years in prison for working for unlicensed nonprofit groups and a minimum of six years for receiving money from abroad, the newspaper said.
Les Campbell, regional director of the National Democratic Institute, said none of the Americans have been served with papers to appear in court, CNN reported.
U.S. officials, who have threatened to cut $1.55 billion in aid to Egypt, say they have tried to find Egyptian counterparts who might intercede, but Egyptian leaders say they cannot intervene in the judicial process, the newspaper said.