"We currently co-operate across a wide range of conventional defence and security areas, and I think this should continue.
"Given our shared challenges it makes no sense for Scotland to walk away from our neighbours when we could and should work together.
"With independence Scotland can get rid of Trident and operate as a dependable conventional ally just like Norway and Denmark."
Surveys of SNP members and voters have shown support for the Nato policy change, according to the party. A recent YouGov poll found that 75% of respondents wished an independent Scotland to remain within Nato and 11% wanted to withdraw.
MP Mr Robertson has said Scotland's continuing membership of Nato would be on the condition of an agreement that Scotland would not host nuclear weapons.