"U.S. Soccer will vote for Prince Ali bin Al Hussein for next president of FIFA," Gulati tweeted on the eve of the global football body's presidential vote.
"This is a vote for good governance & promise for our game," added Gulati, who is also a member of FIFA's powerful executive committee and is in Zurich, Switzerland, for the FIFA congress.
Meanwhile, Victor Montagliani said Canada will instead support the only other candidate, Prince Ali bin Al Hussein of Jordan.
"Our (Board of Directors) met and has made the decision of voting for Prince Bin Ali Hussein as we cannot support the current political leadership of FIFA," he tweeted.
"We want to be front and center on ensuring that the reforms that happens in world football are done in a transparent way but quicker fashion," he said.
Blatter, who is standing for a fifth mandate as FIFA president, has flatly rejected calls to step down even as soccer's global governing body has been engulfed in the worst crisis of its 111-year history.
Nine soccer officials and five sports media and promotions executives were hit on Wednesday by U.S. federal prosecutors with corruption charges allegedly involving more than $150 million in bribes.