Definition of "stepped-up"

Austria is a prime destination for smuggled people heading for the heart of the EU via Hungary from the Balkans. For many migrants, the Hungarian route remains an option despite stepped-up border patrols and a steel fence built by Hungary after the EU’s 2015 migration crisis.

2023 May 23, Lisa O'Carroll, “Austria tightens border controls as Hungary frees convicted people smugglers”, in The Guardian‎