The search area for missing Australian soldier and Canberra man Paul McKay will be expanded, as clues about his whereabouts remain elusive a fortnight after he was last seen near Saranac Lake in New York state.
Mr McKay went missing in a remote region near the Canadian border just before the polar vortex - which dropped temperatures below -30 degrees - hit the area. His last communication was an email to his father on December 30, where he left him all his possessions. This and other information lead police to believe "he didn't plan on going back".
The efforts of more than 40 rangers and volunteers across the weekend reportedly yielded no clues, Saranac Lake police chief Bruce Nason said on Monday, US time.
''There was nothing of significance that was found during the ground search, but the ground search continues,'' he said.
A statement from the state department of environment and conservation said forest rangers would expand the primary search area from Tuesday, covering areas including trails, paths and drains to locate any clues - such as tracks, gear or garbage - for the missing 31-year-old's location.
Volunteers will not be needed for the search efforts planned during this period, the statement said, after 32 volunteers from multiple search and rescue teams took part in the intensive ground effort on Sunday, and 26 on Saturday.
More than 20 forest rangers and volunteers were set to search for the missing Afghanistan veteran on Monday, US time, including a dog team.
''Sunshine and above freezing temperatures improved search conditions slightly, but the presence of snow, ice, thick vegetation, wetlands and streams made for treacherous footing,'' the department's statement said.
Captain McKay was last seen in winter clothing and carrying a large backpack on December 31, two days after arriving in the US.
The ABC reported the search will continue another five days before authorities decide whether to scale it back.
Captain McKay's LinkedIn page reportedly said that after earlier overseas service, he spent 10 months in Afghanistan until January 2012. It said he was a battle captain on shift at Sorkh Bed Forward Operating Base in October 2011 when an Afghan soldier opened fire on a group of 10 Australian soldiers, killing three and an interpreter, and seriously injuring seven other Australian troops.
The LinkedIn profile has now been removed.