Gordon Strachan says Scotland are now harder to beat after his side secured a goalless draw with the USA in a friendly at Hampden.

The Scots continued to show signs of progress under Strachan as they frustrated an American side that had won 15 out of their last 16 matches.

The result was in marked contrast to the humiliating 5-1 defeat Scotland suffered at the hands of Jurgen Klinsmann's side in May 2012 under Strachan's predecessor Craig Levein.

And after ending yet another unsuccessful World Cup qualifying on a high with wins over Macedonia and Croatia, Strachan was happy with how his side held the Americans at bay but said they must improve their passing as they look ahead to the start of European Championship qualification next year.

"I would have loved to have won tonight but I think a draw was about a fair result," Strachan said.

"To win these kind of games we have to be very sharp. That will come, I'm sure it will.

"It wasn't a great game, that's for sure. It was two teams who knew how to stop people playing. It's easier to coach how not to lose goals than it is to score goals.

"Usually scoring goals are down to good moves or individual ability or something really different. That's what we have to work at to win games.

"We have one or two things to work on and we have to work on our final pass. We are doing fine retaining the ball, but we have to find these passes. If we get that then we will beat teams.

"They are up there with Belgium in the physical side. They were big, big boys and to beat them your passing has to be sharper."

Former German international Klinsmann had been in charge of the American national side when they thrashed the Scots in Florida and he said the improvement in Strachan's side was dramatic.

"I think you can clearly see this is a Scottish side that is on its way up. They confirmed what we have already seen in the last couple of months," Klinsmann said.

"It is a team that can hurt you at any moment. They have good players and they have a certain presence on the field.

"They were ready for the fight so therefore I think overall it's a fair result.

"There is no comparison. It is a different side. The compactness, how focussed they are and how serious they are doing their jobs -- they have got the message from Gordon.

"They've got a point to prove and they want to go and build the team towards the Euros in 2016 and you could sense that from the beginning. They were not holding back. They were in there for a hard game. That's what we wanted and we got it."

Strachan was quick to play down the praise from Klinsmann.

"He's got to say that he's a mate of mine. I have played against and we swapped shirts years ago," Strachan joked. "But it's nice to get some recognition."