"Today I want to announce that the government is implementing an immediate suspension on the processing of all new applications from asylum seekers from Sri Lanka and Afghanistan," Evans said.
"The decision has been made in the light of the changing circumstances in both Sri Lanka and Afghanistan.
"
Evans said the move "sends a strong message to people smugglers" but he refused to speculate on whether it would result in stemming the flood of desperate asylum seekers making their way to Australia in often rickety boats.
"The changes we're announcing today send a strong message to people smugglers that they cannot guarantee a visa outcome for their clients," Evans said.
Australia is struggling to accommodate the increased numbers of illegal arrivals, who are dealt with on the remote Indian Ocean territory of Christmas Island.