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.
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Carwyn Jones speaks to our Political Editor Adrian Masters in the final part of our pre-election series on ITV Cymru Wales.
Alexandra Lodge has been to Aberconwy, where Plaid Cymru, the Conservatives and Labour are all hoping to claim victory.
Cloudy skies to start the day, and rather windy with prolonged rainfall during the morning which will be heavy at times.