"USA played well and we know they are a good team but what we focus on is our performance and we know we can play better against that level of opposition.
"A lot of that will come down to a lot more self belief earlier in games. The way we started that game, it made things a lot more difficult for us.
At halftime Readings said the team focussed on trying to build their confidence in their own approach, something which had both positive and negative effects in the second 45 minutes.
"The tactics out there are one thing, and you're always going to look to tweak them, but it's the attitude when we go into those games to actually believe in ourselves because we know we're capable of more.
"In the second half it was almost like we tried so hard to believe in ourselves that we played ourselves into trouble a lot. We were almost trying to make up for the first half where didn't play with that level of belief.
"If you do that and you're trying too hard to play in congested areas against a team as good and as organised as the USA it's quite difficult."
The hosts made an impressive opening in front of their massive home support with Megan Rapinoe heavily involved on the left side of the US attack.
The 17th-ranked Ferns survived a scare in the seventh minute as Rapinoe delivered to the back post where Christen Press fired a shot from 12 yards over the crossbar.
Soon after goalkeeper Erin Nayler did well to tip an Amy Rodriguez effort onto the crossbar and away to safety.
But two minutes later the hosts had the lead when Klingenberg hit a rasping drive from the edge of the area that a diving Nayler could only touch into the net.
Nayler was again called into action 60 seconds later, tipping over a deflected effort from distance before the Ferns began to find a foothold and string their own possession phases together in midfield.
But the Ferns were unable to turn that possession into regular threat of the USA rear-guard with an 8-1 shot count against them in the first period.
It was the USA who could have increased their lead seven minutes before the break, Rapinoe at the centre of it again - delivering a searching long pass to Rodriguez who smashed an excellent first time volley against the post and away to safety.
The hosts created two more opportunities on the hour mark; Alex Morgan firing wide when through one-on-one with Nayler while Rapinoe's shot from the edge of the box was saved well by the New Zealand goalkeeper.
Ten minutes later the Ferns again escaped twice more, Nayler getting hand to a cross before the ball was returned from the byline to an onrushing Rapinoe who turned her shot over the bar.
But the visitors' luck ran out in the 75th minute, Chalupny receiving from a short corner routine from Rapinoe and firing in from the angle from 12 yards. Still recovering from that blow, three minutes later Johnston headed home a free kick from 12 yards over the outstretched arm of Nayler.
Three minutes later the hosts were 4-0 up after turnover in their own third was released to substitute Morgan Brian who slotted home across Nayler and in off the post.
The two sides meet again on Tuesday (NZ time) in St Louis in a training game.
