President Donald Trump is preparing to reintroduce a plan aimed at significantly reducing drug prices by linking what the U.S. government pays for certain medications to the lower prices charged in other countries, according to three sources who spoke with Politico.

Next week, Trump is expected to sign an executive order directing his administration to implement the “most favored nation” policy for a selected group of drugs covered by Medicare. The initiative would use existing executive authority to lower costs, the sources said.

The proposal is still under development and may be revised as White House aides continue to refine the details, according to individuals involved in the planning who spoke anonymously to discuss internal discussions. Politico reported that President Trump has not yet given the plan his final approval.