(Recast) Roundup: Australia under intense pressure to take more Syrian refugees, bomb IS

Australian Prime Minister Tony Abbott on Tuesday is facing increasing pressure from all sides of politics to announce an increase to Australia's refugee intake for 2015.

Abbott has previously indicated that Australia will be taking a higher proportion of Syrian refugees in the wake of the humanitarian crisis facing the Middle East, but has not commented on whether the country's quota of 13,750 will be increased to cope with demand.

The federal opposition is pushing for an additional intake of 10,000 refugees, while the Greens want to take in 20,000.

Australia's Foreign Minister Julie Bishop has been in contact with Immigration Minister Peter Dutton who is in Europe discussing the Syrian refugee crisis, but said the government is yet to work out the final details.

"These are matters for the prime minister to announce," she told the Nine Network on Tuesday.

"There are a number of issues to be determined. When you re- settle people permanently you have to ensure you have the services in place."

"These are matters we are working through. Some countries have just made announcements."

Bishop said Australia was set to announce an increase to the quota of 4,400 additional refugees but said the Syrian crisis had forced the government to rethink the number.

She said the decision would take a "few days at least" to make sure the government had the appropriate services in order.

"That (number) would have been announced this year, but now, because of this crisis, we are reconsidering and we will do what we can," she said.

"The prime minister will announce this when Peter Dutton reports back to him with the details."

The government has also indicated it would likely give preference to "persecuted minorities" such as Syrian Christians, echoing calls from Christian leaders to do more.

Sydney's Catholic Archbishop Anthony Fisher said Australia should "honor" the ties the nation has with Syrian Christians.

"There are concerted campaigns to drive Christians from the Middle East," he told News Corp on Tuesday.

"Other groups are also suffering badly and being persecuted but many Syrian Christians have relatives and a cultural affinity in Australia and we should be honoring those ties and connections."

Meanwhile, the United Nations has called on Australia to contribute more to the crisis, asking for increased funding for humanitarian assistance in the Middle East.

The Australian head of the United Nations High Commissioner for Refugees (UNHCR) said the refugees were not receiving adequate assistance, and Australia had "not yet provided money" to the refugee operation "thus far in 2015."

Bishop said the Liberal government was deciding on how it could best help the European migrant crisis.

"We are taking the advice of the UNHCR and the International Organization for Migration," she said.

Also on Tuesday, Bishop hinted that Australian bombers could join the fight in Syria as early as "this week".

Canada and Britain has already extended its aerial combat against Islamic State into Syria from Iraq, and Bishop said the committee charged with determining the next step would come to a decision in the coming days.

"I note that Great Britain took part in airstrikes last night. The Canadians are taking part. And Australia will give due consideration to the request because we are part of the air strikes over Iraq," Bishop said.

"Our National Security Committee will consider that during the course of this week." Endi