ZAATARI: Russian President Vladimir Putin is undermining international efforts to end the Syrian civil war by bombing opponents of Islamic State in an attempt to bolster Bashar al-Assad, British Foreign Secretary Philip Hammond said on Monday.

In a clear sign of frustration with the Kremlin, Hammond scolded Putin for paying lip service to a political process aimed at ending the civil war while also bombing opponents of Assad who the West hopes could shape Syria once Assad is gone.

When Russia began air strikes in September, Putin tilted the war in President Assad's favour, after major setbacks earlier in 2015 brought rebel groups close to the coastal heartland of his Alawite sect

"It's a source of constant grief to me that everything we are doing is being undermined by the Russians," Hammond told Reuters at the Zaatari refugee camp in Jordan, about 10 km (six miles) south of the border with Syria.

"The Russians say let's talk, and then they talk and they talk and they talk. The problem with the Russians is while they are talking they are bombing, and they are supporting Assad," Hammond said.

Russia says it targets a range of militants in Syria, not just Islamic State, although it insists it focuses on IS. Russian officials say the West is playing with fire by trying to topple Assad.

On Monday, Russia's Defence Ministry said it had conducted 468 air strikes in Syria in the past week and hit more than 1,300 "terrorist" targets, Russian news agencies reported. The ministry also said it had delivered more than 200 tonnes of aid to the besieged Syrian town of Deir al-Zor in January.

But rebels and residents say the Russian air strikes are causing hundreds of civilian casualties in indiscriminate bombing of civilian areas away from the frontline.

"Since the Russian intervention in Syria, the dribble of people who were perhaps going back from these camps to Syria has stopped dead, and there is a new flow coming in because of the actions the Russians are taking - particularly in southern Syria along the border just a few kilometres from here," Hammond said.

PUTIN'S MIND

Russia's intervention had been a major setback for international efforts to find a political solution to the crisis, Hammond said. The effect of the intervention was to strengthen Islamic State, he said.

"The Russians say they want to destroy Daesh but they are not bombing Daesh: they are bombing the moderate opposition," Hammond said, using an Arabic acronym for Islamic State.

"Less than 30 per cent of Russian strikes are against Daesh targets," Hammond said. "Their intervention is strengthening Daesh on the ground - doing the very opposite of what they claim to be wanting to achieve."

But he said that it was difficult to discern whether the Kremlin's support for Assad was changing, because Putin was impossible to read.

"The thing I have learnt, watching Putin first as Defence Secretary and now as Foreign Secretary, is that it doesn't matter how much you watch, you cannot see anything - completely inscrutable," he said.

"We have no idea what the game plan in the Kremlin is. We don't know. There are no councils discussing these things. It is what is going on Mr Putin's head."

Asked if the Iranians were being more helpful than the Russians, he said: "I don't think either of them is being particularly helpful to the peace process.

"The Russians and the Iranians are working hand in glove with the Syrian regime, and the Iranians are at least as hard-line as the Russians about seeking to ensure the preservation of the Syrian regime."