Why did Frodo Volunteer to take the Ring?

[Maédhros]

From The Lord of the Rings:The Council of Elrond

No one answered. The noon-bell rang. Still no one spoke. Frodo glanced at all the faces, but they were not turned to him. All the Council sat with downcast eyes, as if in deep thought. A great dread fell on him, as if he was awaiting the pronouncement of some doom that he had long foreseen and vainly hoped might after all never be spoken. An overwhelming longing to rest and remain at peace by Bilbo's side in Rivendell filled all his heart. At last with an effort he spoke, and wondered to hear his own words, as if some other will was using his small voice.
`I will take the Ring,' he said, `though I do not know the way.'

Why did Frodo volunteer to take the Ring, because he felt that it was his duty or because he didn't wanted to be kept away from the Ring.