By Eoin Blackwell, AAP Papua New Guinea Correspondent
Australia is preparing to send refugees to a facility on Manus Island within weeks following negotiations with the government of Peter O'Neill.
"I refute that totally," Mr Kua told AAP.
"I don't see how one could possibly say that PNG has inadequate regulatory or legal framework to deal with the issues when we have one of the best constitutions in the world in as far as protection of human rights is concerned.
"You cannot find a codified set of human rights in Australia, whereas we do. It is part of our constitution."
In his October 9 letter to Mr Bowen, Mr Guterres said the UN agency was concerned about the Pacific nation's failure to sign treaties against torture, as well as the lack of procedures for the determination of refugee status.
"We recognise that efforts are presently being made to identify and train a small cadre of officers in asylum and refugee issues," Mr Guterres was quoted as saying in PNG and Australian media.
"Over time, capacity will improve but, depending on the scale and complexity of the task and processing cases and protecting refugees under the bilateral arrangements, it will likely remain insufficient for an important period of time."
The Manus facility, located at a naval base on the tiny island, is currently being rebuilt by Australian defence force personnel to house as many as 600 refugees.
Mr Kua said PNG was ready and able to handle the intake.
"Where detailed work is required, that will be developed and is being developed and will initially take the form of an administrative management agreement between Australia and PNG to set out the functional details," he said.
Australia has entered a similar agreement with Nauru.
Australian Human Rights Commission president Gillian Triggs has just returned from a UN fact-finding mission on Christmas Island and says refugees there are concerned about being sent to Nauru.
"We asked a lot of questions. Obviously I'm there to look at the human rights standards and the 150 or so people I talked to either in groups or individually almost invariably were very grateful for the facilities and their treatment," she told the ABC on Friday.
"But their enormous mental anxiety lay with the fear that they would be transferred to Nauru, that their assessment would not take place for some months and would not be over for many years."
She said facilities on Christmas Island were nearing capacity and overcrowding was becoming an issue.
"I think the facilities for a relatively short period of four to six weeks' transfer assessment are adequate for modest numbers," she said.
"The great difficulty is that the numbers are rising and numbers of families are rising, and that is where what would appear to be appropriate facilities become crammed and overcrowded facilities."
Meanwhile, Australian authorities have intercepted a boat carrying 70 people off the Cocos (Keeling) Islands.
It's the fourth boat arrival in two days, taking the total number of people who have been picked up since Tuesday to 334.
The new arrivals will be taken to a detention centre on Christmas Island for security and health check