The immensely popular Putin is constitutionally barred from seeking a third consecutive term, but supporters have called for a referendum on amending the country's laws to allow him to stay in power.
"Despite the fact that I like my job, the constitution doesn't allow me to run a third time in a row," Putin said during a nationally televised question-and-answer session.
The Russian leader also vowed that the killers of a top Central Bank regulator and a well-known investigative journalist would be brought to justice. Putin also hailed the oil-rich country's robust economic growth rate of about 7 percent.
With his popularity high, Putin sees the session — his fifth since taking office in 2000 — as an opportunity to show he can respond directly to voters' concerns. He said the trust Russians have in him will allow him to keep influencing the country after his presidency.
"Even having lost the powers and the levers of presidential power and not tailoring the basic law according to my personal interests, I will manage to retain the most important thing that a person involved in politics must cherish — your trust," he said. "And using that, you and I will be able to exert influence on the life of our country and guarantee its development."
During the broadcast, Putin reeled off statistics, chided North Korea for its nuclear test, pledged to protect agricultural producers and vowed his government would strictly monitor all companies, including foreign ones, for environmental violations.
"In all, I can say we are satisfied with how the country is developing, including the economy," he said.
Dressed in a dark blue suit and striped tie and seated at a rectangular table, the Russian president gestured and pointed as he fielded questions, as if giving a lecture.
The recent killings of top Central Bank regulator Andrei Kozlov and investigative journalist Anna Politkovskaya have stoked fears that Russia is returning to the violence of the 1990s, when business disputes were commonly resolved through shootings and bombings.
Putin said contract killings had declined in recent years and authorities were becoming more successful in cracking down on financial crimes.
"The obligation of the state is to bring any such investigation to the end — this concerns the killings of mass media representatives and killings in the economic sphere," Putin said.
The program had correspondents from the state-run television network relaying questions from small crowds in certain cities around the vast country, as well as people phoning in or sending e-mails and text messages.
It was impossible to tell whether the questions were arranged in advance or questioners coached. During past question-and-answer sessions, critics alleged that authorities and state television reporters screened questions and selected audiences to go live with Putin.
Several Western oil companies that control energy projects in Russia have come under intense environmental scrutiny in recent months, which analysts say reflects a Kremlin drive to increase the state role in the strategic oil and gas sector. Foreign projects facing pressure include Sakhalin-2, a multi-billion-dollar liquefied natural gas development led by Royal Dutch Shell PLC.
"Environmental agencies in collaboration with ecological non-governmental organizations will thoroughly monitor compliance with current legislation," Putin said.
He said Russia's economic growth would reach 6.6 percent this year, noting the government had paid off its Soviet-era debts ahead of time. He said real income had grown about 11 percent this year.
On North Korea, Putin called its nuclear test "inadmissible" but cautioned that pressuring the country could be counterproductive. He said the way to resolve the crisis would be to return to six-nation talks aimed at persuading North Korea to give up its nuclear program.
"One should never lead the situation into an impasse, one should never put one of the negotiating sides in a position from which it virtually has no way out but one: an escalation of the situation," he said.
Putin also addressed a diplomatic row with Georgia that prompted Russia to cut off air and land transport routes to the ex-Soviet republic.
He told one questioner that Russia was not seeking to incorporate two Georgian separatist regions where most citizens have been granted Russian citizenship. Georgia has accused Russia of encouraging the separatists.