Is it ever said in the Pali Canon that Nirvana cannot be attained?

Is there any sutta in the Pali Canon which describes the supramundane view that Nibbana cannot be attained? I'm looking for a verse or quote from the Pali Canon which describes Nibbana as unattainable or unrelinquished based on the fact that is unconditioned. Ie, not from the ordinary conventional sense of attaining a possession or attainment of a goal, but rather from the supramundane where Nibbana is unconditioned. Does such a sutta, passage, or verse exist?