Local media reported that voters in several counties in Pennsylvania had reported that touch-screen voting machines had not been recording their ballots correctly.
"Were going to see how things play out today. Hopefully theyll play out well and hopefully we wont have to worry about it, meaning hopefully well win," Trump said in a telephone interview on Fox News. "I want to see everything honest".
Pennsylvania is one of a handful of states that rely on electronic voting machines without a paper backup that allows officials to double-check the outcome, if challenged, Reuters reported.
The machines can record votes incorrectly if they are not calibrated properly, a problem that is magnified as the screens degrade with age. The Pennsylvania Secretary of States office did not immediately return a call seeking comment.
Trumps campaign also sued election officials in Nevada, arguing they violated state law by allowing voters during early voting on Friday to line up to cast ballots at a Las Vegas polling location after the time when polls were supposed to close. A Nevada judge on Tuesday rejected Trumps request for records from the polling site.
Nevada state law says voters who are in line when the polls close must be allowed to cast their ballots.
At a court hearing in Las Vegas on Tuesday, a county attorney argued that election officials already preserve records.