Kihuen, a member of the US House of Representatives from Nevada, is accused of making unwanted advances toward a former campaign staffer and a lobbyist during last year’s election campaign and his tenure as a state legislator.
"I want to state clearly again that I deny the allegations in question,” the 37-year-old first-term congressman said in a statement on Saturday.
"However, the allegations that have surfaced would be a distraction from a fair and thorough discussion of the issues in a reelection campaign. Therefore, it is in the best interests of my family and my constituents to complete my term in Congress and not seek reelection," the statement added.
A day earlier, the House Ethics Committee said it was opening an investigation into the allegations. Kihuen said in his statement that he was “committed to fully cooperating” with the probe.
Last month, Kihuen’s campaign’s finance director accused him of inappropriately touching her body and making lewd comments to her.
The lawmaker was hit by more accusations last week, when an unidentified woman told local paper the Nevada Independent that he had made similar moves on her as well, while sending her hundreds of suggestive text messages.
House Minority Leader Nancy Pelosi has already called on Kihuen to resign. The lawmaker, however, insists Pelosi and other Democratic leaders knew of the allegations before campaigning for him.
“They looked into them. They didn’t find anything, and they continued investing millions of dollars in my campaign. They went out there and campaigned for me,” he said.
The scandal puts Kihuen next to a string of other Congress members who have been forced to resign or not run for re-election following a spate of sexual harassment claims that have shaken the US political scene.
The list includes such big names as Democratic Representative John Conyers, Republican Representatives Trent Franks and Blake Farenthold. Democratic Senator Al Franken has also announced his resignation after multiple claims of groping and unwanted sexual advances.