New plans to integrate Army reservists with regular troops will see reservists given more training and longer notice of mobilisation.
The Defence Secretary Philip Hammond is expected to announce later that he wants Territorial Army (TA) recruits who are ready to make themselves available for deployment.
The plans come after announcements earlier this year which will see an increased reliance on reservists after the regular Army is slashed by 20,000.
The cut in regular soldiers to 82,000 is being accompanied by a doubling in the number of so-called weekend warriors to 30,000.
More top news
The Defence Department is already in the middle of a congressionally-mandated review of the space force issue.
Detectives have charged 19-year-old Bilal Mumin with murder, grievous bodily harm and possession of an offensive weapon.
Members of the RMT on Arriva Rail North (Northern) walked out for 24 hours, with more stoppages due on Thursday and Saturday.