"USA have strength in depth in every position and some of the best players in the world. They are very hard to break down and have numerous quality attacking weapons at their disposal," Readings said.
"They have a lot of pace throughout the team and are physically imposing. They are strong in all moments of the game and do not allow opposition to easily find any sort of rhythm."
Readings has named a settled squad for the tour with several youngsters such as Stephanie Skilton, Megan Lee and Meikayla Moore coming into the squad, highlighting the strength in depth of the junior sides.
"The fact that we can easily bring young players such as Stephanie, Megan and Meikayla into a settled squad shows how much depth of talent there is available," said Readings.
"It's a testament to both the players and the people behind the junior and young Football Ferns that there is such talent available for selection."
Football Ferns squad:
(Caps/goals in brackets)
Goalkeepers: Jenny Bindon (76/0), Erin Nayler (6/0).
Defenders: Abby Erceg (86/4), Anna Green (56/7), Elizabeth Milne (5/1), Ria Percival (83/8), Ali Riley (74/1), Rebekah Stott (13/0), Meikayla Moore(1/0), Megan Lee (0/0).
Midfielders: Betsy Hassett (53/6), Katie Hoyle (77/1), Annalie Longo (53/1), Kirsty Yallop (69/11)
Forwards: Helen Collins (8/0), Sarah Gregorius (43/17), Amber Hearn (74/35), Rosie White (48/10), Hannah Wilkinson (46/15), Stephanie Skilton (0/0).