U.S. Senate candidate Tim Kaine has joined the chorus of legislators, including House Majority Leader Eric Cantor, R-Va., in calling for U.S. Rep. Anthony Weiner, D-N.Y., to resign after Weiner admitted to sending lewd photos of himself via Twitter.

"Lying is unforgivable," Kaine a Charlottesville area TV station. "Lying publicly about something like this is unforgivable, and he should resign."

Weiner had initially denied sending the photos, but admitted to doing so Monday while insisting that he would not resign. House Minority Leader Nancy Pelosi, D-Calif., has called for an ethics investigation into the matter, and Senate Majority Leader Harry Reid, D-Nev., refused to support Weiner.

"I wish there was some way I could defend him, but I can't, okay?" Reid said.

Kaine, running for the seat currently held by retiring U.S. Sen. Jim Webb, D-Va., entered the fray over Weiner at a time when many Democrats have remained mum on the sidelines.