Klinsmann also said his players had earned the respect of their opponents with a battling performance as they prepare to face the three-time World Cup winners on Thursday in Recife needing at least a point to guarantee a place in the last 16. (Agencies)
"We would have been very happy with four points from the opening two games," Klinsmann said.
"But conceding a late goal was a bummer that we have to swallow. We felt very confident after we turned it around,” he added.
The result means the US are in second place, level with Germany on four points, while Portugal are third with one along with Ghana and face a tough task to reach the last 16.
"It was very emotional for all of us: the players, the fans, the bench but we have to move on and move on quickly," Klinsmann said.
"Portugal is off the table, we have to recover for the game against Germany because the World Cup is always about the next game,” he added.
Just when it looked as though the Americans had secured a come-from-behind victory with goals from Jermaine Jones and Clint Dempsey, Portugal substitute Silvestre Varela scored with a flying header from a Cristiano Ronaldo cross.
Klinsmann, who won the World Cup as player in 1990, complimented Ronaldo's pinpoint cross, which he said followed a series of errors by the U.S.
"Goals always happen on a sequence on mistakes and although we had three centre backs on the field they couldn't manage to cut out that cross by Ronaldo and it was a very good cross," Klinsmann said.
Despite needing at least a draw against Germany to make it to the knockout round for the fourth time in the last seven tournaments, Klinsmann said the U.S. would aim for a victory.
"The U.S. are known to give everything in every single game," Klinsmann said.
"We have that fighting spirit and determination to try to win every game and therefore we will go for a win against Germany,” he added.
He said he did not expect a call from his friend Joachim Loew, the Germany manager who was assistant coach when Klinsmann led his country to third place as hosts at the 2006 World Cup.
"There will be no such call. We are good friends but we are both here to do our jobs. There is no time right now to have friendship calls,” he said.
Klinsmann also said his players had earned the respect of their opponents with a battling performance as they prepare to face the three-time World Cup winners on Thursday in Recife needing at least a point to guarantee a place in the last 16.