Garrisoning

verb

1. To assign troops to a military post.
2. To convert into a military fort.
3. To occupy with troops.

   "'Establishing a land bridge through Mariupol to Crimea would take tens of thousands of troops. So would garrisoning eastern Ukraine.', http//www.economist.com/news/briefing/21615605-now-willing-use-russian-troops-more-or-less-openly-eastern-ukraine-vladimir-putin-has"