Like the Willie Nelson song, Liam Neeson's heroes have always been cowboys so when he was offered the chance to do a Western he jumped at it.

Neeson stars with fellow Celt Pierce Brosnan in Seraphim Falls, a throwback Western about an epic chase involving two desperate enemies. Even though he says he had some reservations about the script, he was mad keen to do a cowboy picture.

"Even before Clint Eastwood, my hero was Audie Murphy in those B-movie Westerns that he made every four or five weeks," he smiles.

"I just absolutely adored them, and that whole Western myth - Pierce and I were both steeped in it as children. So to get the chance to make a Western and ride horses and shoot guns and wear cowboy hats, I mean just on that basic elemental level it's a joy."

But there was more to it than just playing cowboys.

"These men hardly speak at all," he says. "It's figures on a landscape, how they are reduced to their elemental level at the end of the film. And yet out of that comes this extraordinary act of forgiveness from the pair of them."

Brosnan plays Gideon, a man pursued by Neeson's Carver, who is determined that Brosnan should suffer for what he has done.

Neeson compares the character to Captain Ahab in Moby Dick in his single-minded obsession with vengeance.

That said, he wouldn't have swapped places with his countryman when it came to shooting in mid-winter in New Mexico, a place that's nowhere near as warm as it sounds.

"Pierce had it rougher than I did," says Neeson. "He had to get in the water a few times, and be naked. I always had my bearskin coat on.

There was one time we were out on the horses and gradually going into a gallop just following our stunt guys.

And my stunt guy, Mark Renfell, he went round the corner and his horse went into a gopher hole and he and the horse just rolled over. It was terrifying. He got up and said, I kind of enjoyed that!'"

Curiously this is the first time Neeson and Brosnan have worked together, though both auditioned for the role of James Bond at various stages.

"I think every actor in Great Britain was seen at one time," Neeson says. "I was courted after Schindler's List. But I was thrilled Pierce got it - he was a wonderful Bond."

Describing Brosnan as one of the good guys Neeson did lament that the nature of the script in Seraphim Falls means they had few scenes together.

"I was usually up first, working in one location, and while I was getting the make-up cleaned off, Pierce was getting in the make-up chair to start his day's work in the same location," he explains.

"There were lots of days like that where we passed in the make-up chair."

But what they missed out on at work they made up for by socialising.

Neeson points out with a smile that there weren't many pubs in that part of the world but says they were still well looked after.

"We moved about three or four times all around the state.

At one point we were close to the Mexican border staying in this little motel in the middle of nowhere.

"We were sharing it with the border patrol police so when we were coming in after finishing our day's work, these guys were just going out for their shift.

"And their shift was like one guy in a truck patrolling 70 miles, armed to the teeth.

"We got to know them over the weeks and they told us some hair-raising stories - mainly to do with drugs.

"And of course, they were totally intrigued by what we did."

Seraphim Falls was a departure for Neeson who has made a name for himself playing historical characters.

So far his roles include Michael Collins, Alfred Kinsey and Oskar Schindler. Now he is about to add Abraham Lincoln to the list.

Steven Spielberg has cast him as the iconic US President in a film that should start shooting next year.

"There's over 2000 books written on Lincoln, believe it or not, and I've read about 10 of them," he explains.

"And I've visited where he was born, I've been down in Washington to the museums and I've had access to all this extraordinary stuff.

"I've touched the Bible he was sworn in on, I've held his wallet, his glasses, his penknife.

"I've touched his signature. I mean, they gave me carte blanche. I'm obsessed with the man now; I've actually fallen in love with him,"

he smiles.