Their 18-month romance has involved a lot of toing and froing between Canada and Britain as Prince Harry's relationship with Suits actress Meghan Markle heats up.

It has now been reported that the 33-year-old is planning to join his girlfriend for Halloween in her hometown of Toronto.

The fifth-in-line to the throne is set to be reunited with Markle, 36 – who is based in the city to film the US paralegal drama Suits – after speaking at a Chicago summit organised by Barack and Michelle Obama later this month.

A source told The Sun that Harry will make the short flight because the couple ''just can't bear to be apart at the moment.''

They added: ''He's planning to be with her for as long as possible, even though she is working during the day filming Suits. They just love chilling out together like any normal couple and Harry adores Toronto.''

Harry is scheduled to make a speech at the inaugural Obama Foundation Summit in Chicago which will be held in the city on 31 October and November 1.

News of the trip comes as it emerged that aides have been instructed to start planning and finding a suitable date for a royal wedding following Markle's meeting with the Queen last Thursday.

Now that the divorcee has met with Harry's grandmother officially, a royal expert believes an engagement is imminent.

Prince Harry kisses Meghan Markle on the cheek at the Invictus Games closing ceremony Getty

Richard Fitzwilliams opined that their engagement announcement will follow the Queen and Prince Philip's 70<sup>th wedding anniversary on 20 November.

He told IBTimesUK: "This report means we can expect an imminent engagement, with Meghan also rumoured to be leaving her TV series Suits.

"Her interview in Vanity Fair set the scene, their appearances at the Invictus Games confirmed their closeness and meeting the Queen was the logical next step before announcing their engagement, which is expected, probably after the Queen and Duke's Platinum Wedding Anniversary, very shortly.

"A summer wedding next year is expected to follow and there will be much speculation about the venue. Media interest will obviously be phenomenal," Fitzwilliams added.