One Direction's Niall Horan has revealed that he can't wait for Olly Murs to join their current headlining tour of North America.

The 'What Makes You Beautiful' star took to social networking site Twitter last night (May 28) and explained to his 3.6 million followers that the 'Heart Skips A Beat' hitmaker is set to join them in Canada later today, joking that "Toronto is not ready for Olly and 1D":

"@ollyofficial u ready bro? Toronto is not ready for olly and 1D, gona be sick!"

Murs soon replied and wrote: "Oi oi @NiallOfficial have landed in TORONTO!! Its on @onedirection tour!! Can't wait to get started!!"

Horan also tweeted about the group's most recent live show and described it as "incredible":

"Philly, that was some of the most amazing scenes ive witnessed in my 18 yrs, was soo hot up there it was wrong, but u guys were incredible."