Like a stealthy agent worthy of Bond status, Sam Smith has sprung out the first preview of his upcoming Spectre theme, as well as the release date.

The singer-songwriter will officially premiere his James Bond theme 'Writing's On The Wall' on September 25, but an iTunes pre-order link for the song has it listed for release on September 28.

The award-winning star also gave fans a very brief preview of what they can expect from the track, and in good Bond theme form, it's awash with grand swooping strings.

"I am so excited to be a part of this iconic British legacy and join an incredible line up of some of my biggest musical inspirations. I hope you all enjoy the song as much as I enjoyed making it," he previously said.

Bond producers Michael G Wilson and Barbara Broccoli added: "Sam and Jimmy have written the most inspirational song for Spectre and with Sam's extraordinary vocal performance, 'Writing's on the Wall' will surely be considered one of the greatest Bond songs of all time."

There's big expectations too after Adele won an Oscar for her work on Skyfall, so all eyes and ears will be on Smith's attempt later this week.

Spectre, meanwhile, will be released in the UK on October 26 and in the U.S. on November 6.