Media playback is unsupported on your device Media caption PM David Cameron: "We need to keep turning up the pressure until Russia decides to behave like any civilised country"

David Cameron has warned that sanctions against Russia will continue to be tightened unless Russian President Vladimir Putin "changes his approach".

The PM likened the situation in Ukraine to Belgium and Poland "being trampled on" to start two world wars in Europe.

"We are not looking for a military conflict," he told a PM Direct event.

But Russia needed Europe and the US more than they needed it, so sanctions would continue until it "decides to behave like any civilised country".

Details of the latest EU sanctions package will be announced later on Wednesday. It is likely to include a new list of Russian oligarchs who are to face asset freezes and travel bans.

There will also be measures aimed at the oil sector, defence equipment and sensitive technologies.

'Take a stand'

Russia has come under increased pressure after the downing of the Malaysia Airlines jet that killed 298 people in eastern Ukraine.

Western nations have said there is growing evidence the plane was hit by a Russian-supplied missile fired by rebels. Russia has denied supplying heavy weapons to the rebels, and Russia and the rebels blame Ukrainian government forces.

At one of his general question and answer sessions, Mr Cameron told water industry workers at United Utilities in Warrington: "We can't be 100% certain yet that it was separatists firing a Russian-built weapon, but that looks by far the most likely explanation."

After recalling the circumstances of the two world wars, he said Ukraine was an independent country and "there is no doubt in my mind that it is Russian money, it is Russian people, it is Russian weapons that are being sent in to that country to help the separatists".

Image copyright AFP Image caption President Putin has urged the Russian defence sector to rely less on foreign components

He added: "We're not about to launch a European war, we're not about to send the fleet to the Black Sea, we're not looking for a military confrontation. But what we should do is use the economic power that we have - the European Union and United States of America - to demonstrate to Russia that what Russia is doing is unacceptable."

"We need to keep turning up that pressure... it will be a tightening of the ratchet unless Mr Putin changes his approach - there's still time for him to do that, and he should."

Earlier, Foreign Secretary Philip Hammond said the aim was to put pressure on Russian banks and industrialists - the "cronies around Mr Putin, who will feel the pain personally" - to make them "think very hard about the impact this is having on Russia's economy", said the foreign secretary.

Sanctions are already having significant costs on Russia, with its central bank spending tens of billions of dollars in order to defend the rouble, a senior state department official has told the BBC.

'Unavoidable'

Mr Hammond told BBC Breakfast: "The sanctions package is designed to hurt Russia more than it hurts us, but it would be absurd to suggest that we can impose wide-ranging sanctions on the Russian economy without also having some impact on ourselves.

"So our discussions last week focused on a package which shares the burden fairly across the EU, making sure that the big economies share the pain.

"But if we are going to take a stand against Russian aggression, if we are going to insist on Russia behaving like a civilised nation in the modern world, then we have to be prepared to pay the price for doing that."

Image copyright AFP Image caption Buildings in rebel-controlled Donetsk have come under sustained artillery bombardment

He said the sanctions regime would "go on for as long as it needs to go on".

But he suggested if Russia began to cooperate with the international community over the downing of the Malaysia Airlines jet and ended support for Ukrainian rebels, then the EU could begin to "ratchet down" the sanctions.

He rejected suggestions Britain was likely to suffer most from sanctions, saying Russian banks only made up a small proportion of business in the City.

'Disappointed with the EU'

Media playback is unsupported on your device Media caption Vladimir Chizhov, Russia's ambassador to EU: "The Russian economy.... will survive"

US President Barack Obama has announced new economic sanctions against Russia, including banning people in the US from banking with three Russian banks.

German Chancellor Angela Merkel described the latest EU measures as "unavoidable".

Vladimir Chizhov, Russia's ambassador to the EU, told the BBC: "I am disappointed because the EU is slipping along the tracks that lead nowhere."

Last weekend, the EU subjected a further 15 Russian individuals and 18 entities to asset freezes and visa bans for their alleged involvement in the Ukraine conflict.

The list of 87 targets of EU sanctions now includes the heads of the Federal Security Service (FSB) and foreign intelligence, the president of Chechnya, as well as two Crimean energy firms.

However, UK company BP, which owns nearly 20% of Russian state oil giant Rosneft, has warned that further sanctions against Russia could "adversely impact" its performance.