Microsoft has been dealing with some limitations with Windows on ARM since the platform was introduced a few years ago. One of those limitations was the lack of Hyper-V support, something that was recently added in Windows Insider Preview builds, although likely won't ship until about a year from now. There's only one problem though, which is that you actually can't use Hyper-V to create a Windows 10 VM, because there's no ARM64 installation media.
That might be changing though, as was confirmed during the Windows Insider team's webcast today. Microsoft might end up releasing a VHDX that can be used for virtual machines. Of course, the team would only say that it "might" do it, since things that aren't announced rarely get confirmed. But if it happens, it will happen soon.
According to WZor, it's going to be build 19624, which is the Fast ring build from two weeks ago.
If you're looking for a plain-old ISO, that's not as simple of a task as it sounds. Due to the SoC nature of ARM processors, it makes it harder to have built-in drivers in the installation process. If you have something like a Surface Pro X or another ARM64, you'll still need to get installation media from the hardware vendor.