(CNN) -- The government shutdown has caused Vice President Joe Biden to back out of a keynote address to the annual dinner of the national gay and lesbian group Human Rights Campaign, according to his office Thursday.

Biden had been scheduled to be speak at the Human Rights Campaign's national dinner in Washington Saturday night. An HRC spokesman confirmed that Biden had cancelled.

Biden's office did not specify why the shutdown is keeping the Vice President from the dinner.

The shutdown has already forced President Barack Obama to cancel parts of his scheduled trip to Asia, along with far-reaching impacts across the federal government, with hundreds of thousands of workers on furlough.

Gay rights has become an important issue for Biden, who is thought to be considering a 2016 presidential run.

In June, Biden praised the Supreme Court rulings that struck down part the federal Defense of Marriage law and prohibited California's ban on same-sex marriages.

"I think we'll see the day when it is no longer a debate about whether or not same-sex couples can be married and whether or not they deserve every single civil right every other married couple deserves," Biden said at the time.

--CNN's Steve Brusk and Bryan Koenig contributed to this report.