Russia has no evidence that Iran is trying to build a nuclear weapon, Russian Prime Minister Vladimir Putin said Thursday.

"We have no information that Iran is working on the creation of a nuclear weapon," Putin said when asked by a reporter if Iran was close to making an atomic bomb.

Russia, a veto-wielding permanent member of the United Nations Security Council, is a key player in efforts to force Tehran to allay Western fears that it is trying to make nuclear weapons.

Moscow has previously supported UN sanctions against Iran only after insisting they be watered down and has so far refused to publicly support calls by the United States for the threat of additional sanctions against the Islamic Republic.

When asked if Russia would support international sanctions against the Islamic Republic, Putin declined to answer.

Also Thursday, during a four-hour solo question and answer show broadcast on television, Putin also vowed that Russia would step up its efforts against terrorism.

Some 2 million questions were submitted by telephone or on the internet to Putin's marathon television show, which was similar to previous call-ins he did when he was president. It clearly demonstrated that he continued to call the shots, overshadowing his designated successor, President Dmitry Medvedev.

Putin, who has cast himself as a paternal figure protecting people from terrorism and economic upheavals, said Thursday that the threat of terrorism remains very high following a deadly train bombing that killed 26 people last week. He promised that authorities would act very harshly to root out militants.

We have enough resolve and firmness for that, he said. The bombing last Friday of the Moscow-to-St.Petersburg express train fueled fears that Russia could face another wave of terror attacks. It was the first deadly terrorist strike outside the North Caucasus since the bombings of two airliners and a Moscow subway station attack in 2004.