New Delhi: The "biggest highlight" of 'Tiger Zinda Hai's upcoming love tack 'Dil Diyan Gallan' is that Bollywood's superstar Salman Khan drew a portrait for his former girlfriend and co-star Katrina Kaif on a frozen lake in Austria for the song.

Movie's director Ali Abbas Zafar said, "It is a romantic track that captures the beauty of a mature love story. We have filmed 'Dil Diyan Gallan' in an old school, vintage way to bring alive the romance that two mature people. It is like a classic Yash Chopra song."

"The biggest highlight in this song is the unique Katrina portrait that he has drawn on a frozen lake. We had to shoot on this lake and Salman converted it to a canvas.

We had to source natural colors, as ice doesn't catch all kinds of paints, which didn't come easy. But once we got hold of this, he created a huge 20 feet by 20 feet portrait that features Katrina's face," he added.

The song features the two superstars in their most romantic song to date.

'Dil Diyan Gallan,' is a beautiful song that sums up the love story of super spies Tiger and Zoya.

The movie is based on the 2014 abduction of Indian nurses by ISIL and it first look was revealed by Salman through his official Twitter account on October 18.

The film is all set to hit the theatres on December 22.