Moyes says his squad is six signings short ahead of the season kicking off.
"The truth is we're not getting a lot of the deals over the line at the moment, that's a fact," he said to reporters in Chicago.
"We're desperate to get things moving on because we know time's running out.
"The one thing I'll do is I'll tell the fans straight, and I'm telling it straight at the moment, we're having a bit of a struggle getting ones in quickly.
"My first thought is yes, I'm surprised, because I think Everton's such a big club, with great traditions and the new stadium's an exciting move for us.
"But when you think again about it, we've been in or around the relegation positions for the last five years, not far off the bottom, so maybe there's been reasons for it."