The legendary Welsh singer stated that getting older "bothers" him, and is aware that he will only be able to keep performing for a certain amount of time.
"The thing that bothers me about [getting older], is that time runs out," he told BBC Breakfast.
"I love what I do, the only thing that will stop me is age. That's the thing that I'm aware of. I'm 71 now, will I live to 81? 91? Do I have 10 years? 20 years?
"I won't live another 30 years, it will stop me doing what I love to do."
Jones also revealed that he has yet to decide whether or not to return for a second series of The Voice UK, and will only join if he likes his fellow coaches.
"I don't know, there's a lot involved about who's going to do it. I wouldn't sign unless I knew who the others were. That's how I started it, because I might not like them.
"When I started, you put your act together, you worked the clubs before you get a record contract.
"Now these kids on these talent shows, they get this exposure before they actually get a contract. It's almost in reverse, they're thrown in at the deep end right away."
Sir Tom Jones releases his latest album Spirit in the Room in the UK on May 21.
On his new release, he added: "I wanted to do songs by songwriters that I've admired, but tried to get songs that were not well known."
The veteran performer recently said that he would rather die on stage than retire from singing.
