Immigration Minister Peter Dutton wants to create the "hardest borders possible" for criminals, as he prepares to merge the immigration and customs departments into the Australian Border Force to focus heavily on weaponry and force rather than processing and settlement.

In his first announcement as Immigration Minister this week, Mr Dutton said customs officers would be able to carry guns and personal protection equipment at all Australian airports. The decision, which came into effect on Wednesday, was made to ensure officers could be respond to a number of potential "border-related threats" across an "evolving transnational crime and national security environment".

Immigration Minister Peter Dutton. Credit:Andrew Meares

"The government is committed to ensuring that the future Australian Border Force is as well trained and well equipped as possible, to ensure that the public is protected from the range of new and emerging threats our nation faces at the border," a spokesman for Mr Dutton said.

But the overhaul of the Immigration Department to guard the country's borders, rather than focus on settlement and migration, is causing rifts.