Zach Pfeffer is well aware just how important the next few months are in terms of his USA U20 career.

The 20-year old midfielder played almost a full game for Philadelphia Union in their 2-1 loss to New England Revolution on the weekend before flying straight to Austria to link up with Tab Ramos' side.

The US U20s are currently in camp in Linz as they prepare for the 2015 U20 FIFA World Cup in New Zealand and Pfeffer knows it is a vital stage in his hopes of representing the national team on the world stage.

"Any time you get called up to the national team, it's a huge honor," Pfeffer said.

"It's getting into crunch time leading to the World Cup. There's only about a month left and this is the last camp before (Ramos) picks his team. It's an important camp for me and I'm excited."

The U20 World Cup begins on May 30 so Pfeffer is looking to make an impact for Ramos in the next week before getting back to club duties with the Union.

"Any time you're on the field, you want to show yourself and help the team and do the best you can," he added.

"My focus for the next week is on the national team - and then it's coming back here and getting back to business."