The white paper is expected to outline how reservists will work more closely with full-time regular members of the army.
A £42m budget will be provided for new kit and extra training for reserve forces.
It is also expected to reveal financial incentives for small firms employing reservists.
Concerns over the pressure that would be placed on employers to free up their staff for military duty have been highlighted by Wales This Week.
We are asking a heck of a lot from employers... the majority of Welsh companies are small to medium sized and they can't afford for people to go away for a long period. This will be part of the problem that will have to be solved if we want to make an effective Territorial Army in Wales.
More top news
New proposals to cut the number of Welsh MPs by 11 have been unveiled today. The plan is part of an overall cut of 50 MPs across the UK.
Refugees and volunteers have spoken to our current affairs programme Y Byd ar Bedwar about the refugee crisis on the Greek Islands.
Bulgarian Pulev, who had been the mandatory challenger to the IBF and WBA champion, has been forced to pull out of the fight