Turnbull and Obama discuss Syria on phone

Malcolm Turnbull has discussed the issue of Russian air strikes over Syria with US President Barack Obama.

The pair spoke about the fight against the Islamic State group during a phone call on Friday, with President Obama thanking the prime minister for Australia's help as part of the coalition, the White House said.

They also discussed the involvement of Russia in the country, Foreign Minister Julie Bishop confirmed to reporters in Melbourne on Saturday.

Ms Bishop said Australia hoped Russia would take part in efforts to defeat IS and put an end to the conflict.

When asked if Australia could consider increasing air strikes, she said it was an operational matter for the military to determine.