Meghan Markle. Picture: Yui Mok/Pool via AP, File

Thomas Markle has confirmed he is feeling "OK" after undergoing successful heart surgery, but admitted he will "take a long time to heal".

Meghan Markle's father successfully went under the knife on Wednesday to have stents implanted in his blood vessels, and will remain in hospital for "a few more days".

Thomas - who had to pull out of walking Meghan down the aisle at her and Prince Harry's wedding on Saturday (19.05.18), due to the operation - told TMZ: "I'm OK. It will take a long time to heal. Staying in the hospital a few more days. Not allowed to get excited."

READ: Meghan Markle’s dad to undergo heart surgery

The 73-year-old former lighting director believes surgeons implanted three stents, but he wasn't sure. 

Before his heart op, Thomas revealed medics needed to "clear a blockage". 

He recently said: "They [doctors] will go in and clear [a] blockage, repair damage and put a stent where it is needed."

But Thomas insisted he was devastated about missing out on a piece of "history" by not walking his 36-year-old daughter down the aisle at St George's Chapel, Windsor Castle. 

He said: "I hate the idea of missing one of the greatest moments in history and walking my daughter down the aisle. Of course I'd walk her down the aisle. This is a historic moment. 

"I'd like to be a part of history."

Earlier this week, Harry, 33, and Meghan called for "understanding and respect" to be given to Thomas following speculation he might miss out on the couple's big day. 

A Kensington Palace statement read: "This is a deeply personal moment for Ms Markle in the days before her wedding. 

"She and Prince Harry ask again for understanding and respect to be extended to Mr Markle in this difficult situation."

While it's not yet known who will walk Meghan down the aisle at the royal wedding, the former 'Suits' star's mother Doria Ragland could take on the role.