The cancelation failed to satisfy the protesters, who say they want the government to re-negotiate the agreement with Washington.

Protester Kim Won-yeol said the existing bill should be scrapped completely.

The government had been expected to use its majority in the legislature to push through the ratification last week. But it has repeatedly postponed a vote in the face of fierce resistance from the opposition, which has threatened violence on the floor of the chamber if the government tries to railroad a vote.

Opposition to the pact is focused on a complaint mechanism that would allow Washington to override local laws and go to directly to international courts in the case of a dispute.

The government opposes any changes that would force it to renegotiate the deal, which languished for more than four years before being ratified by the U.S. Congress last month.