Yes, but it’s difficult with longer focal lengths because telephoto lenses naturally give shallower depth of field. To maximize background sharpness:

• Use a small aperture (high f-number).
• Increase camera-to-subject distance.
• Keep the subject as close as practical to the background, if composition allows.
• Compensate for the smaller aperture with slower shutter speed, higher ISO, stabilization, or a tripod.

A depth-of-field calculator can help you see whether your setup can keep both subject and skyline acceptably sharp. In many real-world cases, especially on full frame with 85–135mm lenses, getting a distant skyline truly sharp behind a portrait may require an aperture smaller than your lens offers.

If optics alone won’t get you there, one workaround is compositing/focus stacking: make one exposure focused for the subject and another for the background, then merge them in software.

You can also separate the subject from the scene with lighting rather than blur—for example, adding flash if the light is low.

So: possible in principle, but often limited in practice. A smaller aperture, more distance, and/or compositing are the main solutions.