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PITTSBURGH (KDKA/AP) — As midterm votes are being cast in Pennsylvania and across the country, the U.S. Department of Homeland Security is playing catch-up.

Pennsylvania is one of at least 17 states where election officials have requested on-site risk assessments of their election systems. Nearly half those reviews had not been completed by mid-May, including the one for Pennsylvania, which holds its primary election on Tuesday, May 15.

A spokesperson for the Pennsylvania Department of State told KDKA-TV the security review will not be completed until June at the earliest. A security review by DHS typically takes two weeks to complete.

“In the run-up to the 2016 presidential election, Pennsylvania was the first step to take DHS up on its offer to do such an assessment,” the spokesperson told KDKA-TV. “This initial check in 2016 found no significant vulnerabilities.”

Since the 2016 election, more states have been asking the DHS to review their election systems. That’s caused a backlog.

The security reviews are designed to identify any weaknesses that could be exploited by hackers. The nation’s intelligence chiefs warned earlier this year that Russia remains interested in disrupting U.S.. elections after a multipronged effort to interfere two years ago. that included attempts to hack into the election systems of 21 states.

The DHS has pledged to complete the reviews for every state that asks by November.

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