The Magpies have lined up a move for Harewood as they seek to bolster their attacking options after losing Shola Ameobi to long-term injury.
Newcastle tried to sign Harewood during the transfer window only for a foot injury to delay any move.
But the striker is now back to fitness and is keen to be playing regular first-team football after finding himself well down the pecking order at Villa Park.
His representative Phil Sproson confirmed his client is keen on a move to Newcastle and is hopeful of finalising a deal later this week.
"I believe we are close to agreeing everything and hopefully the move can be finalised later this week," Sproson told skysports.com.
"Talks are ongoing between both clubs and I think they are keen to get it resolved.
"Marlon is back to fitness now and he is ready and raring to go.
"Marlon is very keen on going to Newcastle and playing regular first-team football again."
Newcastle 11/8, Peterborough 7/4, Draw 11/5