PORT MORESBY. Tony Abbott has declared there is a "world of difference" between refugees from Syria and Iraq who will now be resettled in Australia and those from the same countries and have been languishing in detention for more than two years in Papua New Guinea and on Nauru.

The Prime Minister said he was very encouraged by the "big-hearted, generous response" of the Australian people to the government's decision to accept 12,000 refugees from the Syrian conflict.

Then prime minister Tony Abbott meets PNG leader Peter O'Neill in September 2015. Credit:Andrew Meares

While these people had sought refuge near Syria's borders, Mr Abbott said those on PNG's Manus Island and in detention on Nauru had "done a deal with people smugglers to go way beyond the country of first asylum".