Foreign Minister Penny Wong has sharply criticised United Australia Party senator Ralph Babet, accusing him of being absent from Parliament for months while continuing to draw a taxpayer-funded salary.

The heated Senate exchange erupted in parliament on Monday after Babet challenged the government's refusal to import Russian fuel.

He asked whether US President Donald Trump was also a 'disgrace' for supporting purchases of Russian diesel to lower costs for American consumers.

'Minister, six months ago I asked you if it was in the national interest to permit the importation of fuels that originate from Russia. Your answer was: "With respect, Senator Babet, your support for President Putin's regime is a disgrace,"' Babet said.

'I note that a few days ago, President Donald Trump announced that the United States would purchase Russian diesel to help ease pressure on American families.'

'Minister, is the President of the United States also a disgrace?'

Wong responded by mocking Babet on his low attendance.

'Senator Babet, you mentioned the question from six months ago. It is good to have you back, mate. This is the first question you have asked in six months,' she said.

'If you want to talk about what is disgraceful, I think it is disgraceful that a senator rocks up here, takes six months before turning up to do some work, continues to collect a salary and posts holiday photos everywhere.'

Between July and August, Babet shared images of himself on Instagram holidaying in London and Venice, as well as photos from the Emirates First Class Lounge, while parliament was sitting. 

'In between then and now, people have been observing your magical mystery tour on Facebook and Instagram,' Wong continued.

Babet has made just seven contributions in the Senate in the last three months, according to Hansard records. 

 The figures are in stark contrast to other crossbench senators, with independent Senator David Pocock making 98 contributions over the same period.

During that time, Babet was granted a leave of absence from August 11-20 for 'personal reasons'.

The leave appeared to coincide with overseas travel documented on his social media.

Wong also reaffirmed Australia's support for Ukraine.

'We believe Russia's invasion of Ukraine was illegal and wrong. We will continue to stand with Ukraine,' Wong said.

'I understand you want to stand with President Putin against Ukraine. I completely disagree with you and I think that is a shameful position. We will not be changing our position.'

Babet hit back: 'That was an art form. It did not answer a single thing.

'Why don't we put our national interests first as well?'

Wong argued that standing against Russian aggression was itself in Australia's interest.

'It is in Australia's national interest, as a nation of our size, for the United Nations Charter and the prohibition on larger powers violating the territorial integrity of smaller countries to be upheld,' she said.