增加防守力量to strengthen one's defences(Britain); to strengthen one's defenses(US)

• 调集第九十二、六十二军和第九十四军主力增防北平。

  Assemble the 92nd and 62nd Armies and the main force of the 94th Army to strengthen the defence of Beiping.

• 要求承包商要增防安全意识，节日期间值班人员坚守岗位。

  Contractors are required to increase their safety awareness, and on-duty employees must stick to their posts during the holiday period.