WASHINGTON - The top Senate Democrat says Sen. Al Franken should resign as allegations of sexual misconduct against the Minnesota lawmaker multiply.

In a brief statement on Wednesday, Minority Leader Chuck Schumer said he considers Franken "a dear friend" but he has a higher obligation to his constituents and the Senate, and "he should step down immediately."Franken plans to make an announcement on Thursday.About two dozen senators are calling on Franken to resign. In Facebook posts and Tweets, many women said the two-term senator should step aside after a fresh allegation that he forcibly tried to kiss a woman in 2006.Sen. Kirsten Gillibrand wrote on Facebook that while Franken is entitled to have the Ethics Committee conclude its review, "I believe it would be better for our country if he sent a clear message that any kind of mistreatment of women in our society isn't acceptable by stepping aside to let someone else serve."

Sens. Mazie Hirono of Hawaii, Maggie Hassan of New Hampshire, Patty Murray of Washington state and Claire McCaskill of Missouri joined Gillibrand in pressing for Franken to quit.The chairman of the Democratic National Committee also called for Franken to resign.

Wednesday afternoon, fellow Minnesota Senator Amy Klobuchar said in a tweet she "is confident he will make the right decision."

Sen. Franken is denying the latest accusation by a former Democratic congressional aide that he tried to forcibly kiss her after a taping of his radio show in 2006. The Minnesota Democrat says in a statement that the allegation - reported by Politico - is "categorically not true."The senator is facing a Senate Ethics Committee investigation into previous claims by other women that he groped them.