Russian President Vladimir Putin on Wednesday faced what appeared to be a rare unscripted grilling from a Russian woman who asked him how much he earns and whether he could live on her income of $170 a month.

While visiting his native city of Saint Petersburg, Putin had laid a wreath at a political mentor's grave and was approached by people passing nearby, who filmed him on cell phones.

A woman in a hooded coat pushed through and immediately asked Putin: "Please tell me, is it possible to live on 10,800 rubles ($170)?"

"I think it's very hard," Putin said quietly in video footage posted by Russian media.

"Your pay is probably about 800,000 rubles, I imagine," she says.

"Well yes," Putin says, while adding that some in Russia earn far more and "the president doesn't have the highest salary."

The woman, who said she is studying book-keeping and lives on disability benefits, went on to talk about everyday costs, apparently doubting Putin knew the figures.

A trip to the grocery store costs at least 1,000 rubles, she said, while utility bills for a flat cost at least 4,000 rubles.

While Putin shines at public speaking in large auditoriums with usually carefully orchestrated questions, he rarely goes out on the street for unpredictable encounters with members of the public.

On Wednesday, Putin referred to recent policy initiatives to improve lives of families with children, including enhanced child benefits and payouts for the birth of a child.

"Of course you are right, we still have a lot of social problems that the government has to solve," he said.

"Why don't you solve them then?" the woman retorted.

"We are solving them," Putin said.

The woman then asked Putin to pose with her for a photo.

Putin was in Saint Petersburg to mark twenty years since the death of his early political mentor, former city mayor Anatoly Sobchak.