The Unites States is working closely with countries in Southeast Asia on mechanisms to end human trafficking in the region, said President Barack Obama.

Describing human trafficking as a critical problem, Obama said Washington took up the matter seriously with dedicated agencies back home to solve the problem.

He noted that the Trans-Pacific Partnership (TPP) trade deal involving 12 countries including Malaysia also touched on the importance of advancing human rights.

The president said this at a press conference here Sunday before leaving Malaysia after attending the 3rd ASEAN-US Summit as well as the 10th East Asia Summit on the sidelines of the 27th ASEAN Summit hosted by Malaysia.

Obama, who was in the city for three days since Friday, said the requirements on human rights underlined in the TPP were to ensure that prospective partners put in place measures to prevent activities linked to human trafficking.

Obama expressed optimism that the 12 negotiating countries would apsprove the pact, which would see new trade deal being worked out among the members, who represent 40 per cent of world economy.

Malaysia and the 11 other countries - Australia, Brunei, Canada, Chile, Japan, Singapore, Mexico, New Zealand, Peru, the United States and Vietnam successfully concluded negotiations for the TPP, initiated by the United States, on Oct 5, 2015.

For Malaysia, the content of the TPPA and the two impact studies would be tabled in parliament next January.

This will be followed by a debate to decide whether Malaysia should sign the TPPA at end-January 2016. The ratification of the agreement is expected to be realised two years after the signing of the pact.

The US president pointed out that his meetings with the other 17 leaders at the ASEAN-US and East Asia Summit were successful. Obama thanked Malaysia's leadership and hospitality for making these meetings "a successful one".

On his presence in the region, Obama, who had been in Manila for the APEC Summit prior to coming to Malaysia, said the Asia Pacific region was critical for security and prosperity.

"That is why so much of my foreign policy concerns deepening American engagement with this region (and) I am pleased that in this trip, we have made progress across the board," he said.

Obama said he had also invited all ASEAN leaders for a gathering in the United States next year.