After secretive talks, key senators express optimism they are closing in on a bipartisan agreement to toughen the border security requirements in immigration legislation that also offers a path to citizenship to millions living in the country illegally.

Officials said Wednesday night that under the emerging agreement, the government would be able to grant legal status to immigrants living in the United States unlawfully while the additional security was being put into place. No green cards — signifying permanent residence status — could be issued to them until the plan was fully implemented.

The officials spoke on condition of anonymity, saying they were not authorized to disclose terms of a plan that was not yet finalized.

If agreed to, the change has the potential to give a powerful boost to the immigration bill that is at the top of President Barack Obama’s second-term domestic agenda.

(AP)