Sen. Bernie Sanders said Wednesday he supports doctor-assisted suicide, saying terminally ill patients should have the right to decide when to end their own lives.

"If a human being is in a situation where they are going to see their life end in a short period of time, where they are suffering, where they choose no longer to be alive, I think they have the right to make that decision for themselves," the Democratic presidential contender said at a forum hosted by George Mason University.

The Vermont senator, while from one of a handful of states allowing physician-assisted suicide, isn't often vocal about the controversial issue. But in 1999 as a representative, he voted against a House bill banning doctors from providing lethal prescriptions to terminally ill patients.

Sanders' presidential opponent, Hillary Clinton, has been less clear about where she stands on the issue. When asked about it earlier this month, she called it a "critical question" but said she doesn't have an "easy or glib answer."

Just five states allow assisted suicide, with California being the most recent state to approve such a measure. The others are Oregon, Washington, Montana and Vermont.

Sanders expressed support for doctor-assisted suicide when asked about it by Susan Buckley, a volunteer for Compassion and Choices, a group that has been advocating for more states to pass such measures.

"What people really need is greater agency and access to information and options as the end of life approaches," Barbara Coombs Lee, president of Compassion and Choices, said in a statement. "And they want our national and state policy makers to address this need."