Russia only sent troops and tanks to drive Georgian forces out of South Ossetia after President George Bush failed to put pressure on Georgia's president to stop his attacks on the breakaway territory, Vladimir Putin said yesterday. The Russian prime minister told a group of western journalists and experts on Russia that he held two meetings with the US leader during the Beijing Olympics as the crisis began to unfold, but received insufficient assurances from him.

"They [Georgian military forces] launched their attacks at 23:30 [on August 7]. I learned about it the following morning. I spoke to Bush. He said 'No one wants war.' We expected something would happen," Putin said, suggesting that he expected the US to rein in its regional ally in Tbilisi.

"I met him again at the stadium. I can't tell you in detail the content of the conversation, but I had the feeling that his administration wouldn't do anything about stopping the conflict," Putin said. Russian tanks were then ordered to move on the South Ossetian capital, Tskhinvali.

It is the first time that Putin has blamed the US for allowing the crisis to erupt. He was polite about Bush, saying he respected his integrity, but he suggested that the president's advisers had taken the key decisions. "It's a court which makes a king. Maybe the court thought the king shouldn't intervene," he said.

In his trademark blunt language, Putin also issued a direct warning to the UK that relations could never be repaired as long as London hosted dissident exiles such as the Chechen independence advocate Akhmed Zakayev. "Why do you allow Great Britain to be used as a launching pad to fight Russia? If we were to give safe haven to militants of the IRA, with arms in their hands, what would you do? Why can they engage in open anti-Russian activity? That's why it's not possible to build normal relations with Britain," he said.

Zakayev was given asylum in Britain in 2003, the same year as the Russian tycoon Boris Berezovsky. Both were close to the former KGB spy Alexander Litvinenko, whose murder in London in 2006 sent bilateral relations plunging.

Despite his tough language over the South Ossetia conflict, Putin refused to issue threats against the west for supporting Georgia. He accused the US of training the Georgian army before its attack on Tskhinvali last month. "They sent instructors who helped to mobilise the Georgian forces. Of course we had to respond."

Throughout yesterday's three-hour meeting, he blamed the west for being stuck in cold war "anti-Russian phobia", and the American presidential candidates, John McCain and Barack Obama, for "playing the Russian card". This was "only a sign of the candidates' weakness", he said.

Making it clear that any expansion of Nato to Georgia or Ukraine would be unwelcome to Moscow, Putin said it was time to create a security architecture for Europe which reflected the new realities in the continent.

Russia had no imperial aims, he said, and should be credited for dismantling the Soviet Union. "Had it not been for Russia, the Soviet Union wouldn't have been dismantled," he said.

He took issue with the Bush administration's recent decision to install long-range missiles in Poland, ostensibly as a defence against potential missiles from Iran. Iran had no such missiles, he said, and the US missile system's intentions were clear. If the US deployed any missiles, Russia would target Poland. "Our targeting will start as soon as the missiles are deployed," Putin said. "We say, please don't try again to instigate an arms race in Europe."

He criticised the Bush administration for foisting decisions on Europe. The missile decisions "began with bilateral talks with Poland, and then they started to convince Europe it was in their interest". He made the same point about Ukraine's government's decision to seek Nato membership. "Eighty per cent of Ukranians don't want it," he said.

He denied that he was in overall control of Russian decision-making, insisting that President Dmitry Medvedev was the commander in chief. "He's modern, with a liberal democratic view of things and an excellent education. I am sorry it was his lot to have to deal with this crisis. He is a decent man. He had to give the order to send troops to these republics [South Ossetia and the other breakaway region of Abkhazia]. He had to recognise these republics, he couldn't do otherwise. These were his decisions."

Putin made clear that Russia could easily have occupied Georgia and toppled its president, Mikheil Saakashvili. "Our forces were 15 kilometres [nine miles] from Tbilisi. It would have taken four hours to capture Tbilisi. We didn't have that goal."