The German has been in charge of the national side since 2011 and Howard is confident the upbeat attitude instilled in the squad can help them perform well in Brazil.
A quarter-final place in 2002 represents the USA's best performance at a World Cup to date. And, while Howard acknowledges repeating that will be difficult, he thinks there is the belief to keep improving.
"He's made the preparation great," the Everton goalkeeper told the Daily Express.
"Everything off the field is first class, from having our own chef, to travel, everything. He has made everything 10 times better.
"Obviously I am an older player and have seen many things. But the one thing that (Everton boss Roberto) Martinez and Klinsmann have in common is that they are both ultra-positive people.
"With both these managers, there is no catch. That is who they are. It is a breath of fresh air.
"Expectations are high now."
The United States will face Portugal, Ghana and Germany in Group G in Brazil.
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