The request has been accepted and military personnel will join forces with North West Ambulance Service from next week.
The ambulance service is said it is under "extreme pressure" with 25% of its staff currently isolating due to Covid.
But from Tuesday (January 11), 150 soldiers will be deployed to the region to drive ambulances and respond to non-emergency incidents.
The military will work alongside ambulance crews for a "number of weeks", much as it did last year when NWAS faced similar pressures due to Covid.
Director of Operations Ged Blezard said: "It is no secret that the ambulance service, along with the NHS as a whole, has been under extreme pressure for several months.
"Now we are also experiencing high numbers of staff absences due to confirmed COVID-19 cases and isolation, with around 25% of the workforce currently affected.
"As part of our resilience planning, we can make a request to the military for support and feel now is the right time to put the arrangements in place.
"We worked alongside the military last February and March, and it allows us to have more of our vehicles on the road, getting people the treatment they need sooner.
"This frees up emergency ambulances to attend to urgent, life-threatening cases."
Military personnel will receive NWAS training in driving ambulances, manual handling, kit familiarisation and basic life support, similar to the standards of the trust’s patient transport staff who have also been supporting the emergency service throughout the pandemic.
It follows a partnership last winter, when soldiers were deployed to more than 4,600 non-life-threatening 999 incidents. They also helped move patients between healthcare sites around 1,700 times.
Mr Blezard added: "I would like to thank our NWAS team of staff and volunteers for their continued dedication over the last two years. They have been working incredibly hard to deliver the best possible service for our patients.
"Taking this timely intervention to increase our resources means we can carry on doing that while providing extra support for our staff and patients during another challenging period.
"As always, we are here for you in an emergency, and you can assist us by using 111 online if you need urgent care advice and only dialling 999 in a life-threatening situation."