"The travel curbs are mandatory to ensure Covid-19, especially the highly infectious Delta variant, does not spread nationwide," he added.
Manning told The National newspaper in an interview this week that the tests had to be made mandatory after 22 Delta cases were confirmed in Western and that there was a high chance of a severe outbreak, or surge, of Delta in the province.
"New directives and control measures will be out soon. The directives will be for those at border provinces to be tested, now that there is a surge of Covid-19 cases there," he said.
"The test results can take between one and four weeks. All visitors to the border province should have a test done there before returning to Port Moresby or elsewhere," Manning said.
The authorities believe the Delta attack in Western is due to border crossings to Indonesia's West Papua Province and then returning to PNG.
More than 70 education officials led by Education Minister Jimmy Uguro are now in Western's Kiunga attending a week-long conference on the implementation of the National Education Plan for 2020 to 2029.