"I expect if they are reducing at some stage we will come down. We don’t have a massive force, compared to them but we’ll do what we need to do to keep people safe", he told SkyNews.
Wallace said that turn of events would be reflected in a new defence review, which was paused amid the coronavirus pandemic.
"We have a challenge. We will have to build a bigger or another coalition or, in fact, we will just have to faithfully follow them out. That’s something that no one is being happy about", he said.
US Acting Defence Secretary Christopher Miller formally announced plans on Tuesday to cut the number of troops to 2,500 each in Afghanistan and Iraq by 15 January. Roughly 4,500 US armed forces personnel are currently stationed in Afghanistan and 3,000 in Iraq.