US administration officials on Friday said the additional sanctions were also aimed at forcing Syria to crack down on "terrorism".
"The application of additional sanctions under the Syrian Accountability Act is an option," a senior official said. "No final decision has been made."
In May, President George Bush imposed a series of sanctions on Syria, including a ban on US exports other than food and medicine.
He accused Damascus of supporting terrorism, pursuing weapons of mass destruction and failing to stop anti-US guerrillas from entering Iraq.
But some US lawmakers said Bush did not go far enough and were pressing him to go a step further.
They pointed to a report earlier this month by UN Secretary-General Kofi Annan, which stated that Syria had failed to meet a Security Council demand to pull its estimated 14,000 to 17,000 troops out of Lebanon.
The Bush administration is already pursuing action in the United Nations. On Thursday, the United States and France introduced a draft Security Council resolution intended at putting fresh pressure on Syria over its troops.
The draft would ask Annan to report every three months on the issue as a follow-up to a 2 September council resolution that demanded all foreign troops leave Lebanon.