Donald Trump on Monday knocked Barack Obama for receiving the Noble Peace Prize and said he would have one of his own 'if they gave it out fairly.'

The president mocked Obama for not knowing why he was given the prestigious prize shortly after becoming president.

'I would get a Nobel prize for a lot of things, if they give it out fairly, which they don't. They gave one to Obama immediately upon his assent to the presidency and he had no idea why he got it. You know what? That was the only thing I agreed with him on,' Trump said at a sit-down with Pakistani Prime Minister Imran Khan.

Donald Trump knocked Barack Obama for receiving the Noble Peace Prize

Barack Obama in Oslo in December 2009, receiving his Noble Peace Prize

Obama was awarded the Noble Peace Prize in 2009 for his 'extraordinary efforts to strengthen international diplomacy and cooperation between people,' according to the award's citation.

'Only very rarely has a person to the same extent as Obama captured the world's attention and given its people hope for a better future. His diplomacy is founded in the concept that those who are to lead the world must do so on the basis of values and attitudes that are shared by the majority of the world's population,' the citation read.

At the time the award was announced, it was met by criticism from those who said the president, who had not been in office for even a year at that point, hadn't accomplished enough to earn the distinguished honor.

Geir Lundestad, the former secretary of the prize committee, admitted in his 2015 memoir that giving the prize to the newly-elected president did not have the effect hoped for.

'Even many of Obama's supporters believed that the prize was a mistake,' he wrote. 'In that sense the committee didn't achieve what it had hoped for.'

He also revealed the White House considered not sending Obama to Oslo to receive the prize - due to the criticism of Obama receiving the award - but ultimately agreed to do so when they realized it would be a diplomatic faux pas not to attend.

Even Obama said he was 'surprised' to be given the honor.

In an interview with Stephen Colbert about his legacy in 2016, as he was wrapping up his time in the White House, the former president was asked why he got the award.

'To be honest, I still don't know,' he said.

Last year, a group of 18 Republicans in Congress formally submitted Trump's name to the Norwegian Nobel Committee in Oslo, Norway, that picks the winner, for his work with North Korea at the Singapore Summit.

Trump was also nominated by two members of Norway's governing Progress Party.

That year's award, however, went to two activists who worked to end the use of sexual violence as a weapon of war.

Trump met with Pakistani Prime Minister Imran Khan and offered to mediate in the Kashmir dispute between India and Pakistan

Trump's comments on Obama came during his sit-down with Khan in New York where both leaders are in town for the United Nations General Assembly meeting.

The president offered his help - as he has in the past - in negotiating a peace deal between Pakistan and India over the disputed territory of Kashmir.

'If I can help I will always do that,' he said on Monday, adding: 'I am ready willing and able.'

'I have a very good relationship with Prime Minister. Modi. I have a very good relationship with Prime Minister Khan. And if at any time they say you know we have some points we think you can maybe iron out, I think I’d be an extremely good arbitrator,' Trump noted.

The president caused a row with the Indian government last month when he said Prime Minister Narendra Modi had asked him to mediate in the dispute, drawing an immediate denial from New Delhi.

Past winners of the Noble Peace Prize include the Rev. Dr. Martin Luther King Jr., education advocate Malala Yousafzai, former Vice President Al Gore for his work on climate change, International Campaign to Ban Landmines, South African leader Nelson Mandela, Myanmar leader Aung San Suu Kyi, former Soviet Mikhail Gorbachev, Mother Teresa, and Amnesty International.