Prime Minister Kevin Rudd has flagged a three-step approach to tackling the flow of asylum seeker boats, including possible changes to the Refugee Convention, as a second boat disaster in a week resulted in more asylum seeker deaths.

It also comes as a third asylum seeker boat is reported to have come into trouble north-east of Christmas Island.

Mr Rudd is expected to announce a change to Labor's asylum seeker policy as early as this week.

On Wednesday afternoon, he told reporters in Gladstone, Queensland, that the government had the responsibility to adjust its asylum seeker policies in ''response to new circumstances''.

He said the government was working ''methodically through the real possibilities for change which will have a real effect'', before flagging a three-step approach at the international, regional and national level.

''We are looking at this right now globally, in terms of the effectiveness of the Refugees [sic] Convention," he said without further explanation.

Australia was an early signatory to the 1951 United Nations Convention on Refugees, which has been criticised for having an outdated definition of what is is to be a refugee and only protecting people who are able to leave their country of origin.

Mr Rudd said the government was also looking at regional cooperation measures and the refugee determination processes.

''Australia so far has had a reasonably generous approach to the assessment of asylum seekers from around the world,'' he said.

''Those criteria are being looked at afresh. And we'll have more to say about that in due course.''

Mr Rudd said that action at the three levels was the right response  ''to a problem which is not uniquely Australia's''.

Greens leader Christine Milne said she would be very concerned if Australia tried to ''take on the Refugee Convention and undermine it in any shape or form''.

''For Australia to say we're going to abandon international law or excuse ourselves ... that would be completely unacceptable," Senator Milne told Sky News.

Senator Milne said any change to Australia's approach to the Refugee Convention would be a particularly bad thing for Australia to do as it joined the UN Security Council and prepared to host the G20 Summit next year.

Earlier Home Affairs Minister Jason Claire released details of the asylum seekers killed in the latest boat tragedy. Four people died, and another 144 including 19 children were rescued, when their boat capsized in rough seas north on Christmas Island on Tuesday.

Responding to the deaths, Mr Clare said the issue of boat arrivals has become ''poisoned by politics''.

Mr Clare said at a press conference in Sydney on Wednesday that the aftermath of the tragedy was not a time for politics. But he did say that if MPs were going to fix the ''god-awful problem'' of deaths at sea, they would have to work together.

''This is a wretchedly difficult area and its been poisoned by politics. We have been fighting about this for more than 10 years. And the people of Australia are sick and tired of politicians fighting about this,'' Mr Clare said.

He decried the fact that the Coalition and the Greens had not let the Labor government legislate all its policy responses – such as the Malaysia people-swap – to the increase in boat arrivals in recent years.

''When people are dying the government should be given the power that it thinks it needs to stop this happening,'' Mr Clare told reporters.

This came after Opposition Leader Tony Abbott labelled the the situation with boat arrivals a ''national emergency'' and called on Mr Rudd to support the Coalition's policies.

For a second time this week Customs and Border Protection has had to defend its actions over its search and rescue operation. Tuesday night's incident followed a boat sinking last Friday, in which a baby died and eight others went missing, presumed dead.

In a joint press conference with the head of Border Protection Command, Commander David Johnston, Mr Clare said that two Australian navy boats had been escorting the vessel to Christmas Island when it began to lean to one side and passengers began jumping into the water about 6pm on Tuesday.

Even though there had been calls from the vessel earlier on Tuesday, saying its engine had stopped working, the boat had not appeared to be in distress until this point, according to monitoring by Australian authorities.

Mr Clare explained that the operation happened in very rough conditions, with waves of about two metres.

He said the four who died were two women in their late 20s or early 30s, one man in his 20s and one man in his 30s. It is understood the boat's passengers were from Pakistan, Afghanistan, Iran and Iraq.

Rear Admiral Johnston said it was emotionally very difficult for Customs officials involved in the rescues. ''It is a dreadful feeling in the stomach when we hear that a vessel is capsized,'' he said.

Admiral Johnston, along with Mr Clare, praised the rescue efforts of Australian authorities in the rough seas on Tuesday.

''My praise for them is unlimited because of what they've achieved,'' he said, noting that the disaster happened very quickly.

'A national emergency'

Earlier on Tuesday, Mr Abbott told reporters in Mackay that he was happy to support Mr Rudd in legislating changes to asylum seeker policy – if Mr Rudd supported Mr Abbott's stance.

''I'm more than happy to put partisanship aside and support the Prime Minister making the changes that are necessary to stop the boats,'' he said, specifying this meant reintroducing temporary protection visas, ''rigorous'' offshore processing, ''a clear willingness to turn boats around and actually turning boats around where it is safe to do so'' and a ''much better'' relationship with Indonesia.

Mr Abbott repeated his attack on Mr Rudd that he was not only the ''best friend the people smugglers have ever had'' but was also their ''travel agent''.

''It's not good enough, Prime Minister. It's just not good enough. This is a national emergency. It's got to be addressed now. I call on you to stop talking and put in place the real action that's necessary to truly make a difference here,'' Mr Abbott.

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