WASHINGTON (AFP) — The approach of winter will bring tougher conditions to Ukraine including heavy mud, snow and freezing cold that will make military operations more difficult for both sides in the war.

Kyiv — which is fighting to retake areas seized by Moscow — has more to lose from a slowdown that leaves its territory in Russian hands, and time is running out for it to capitalize on recent battlefield successes before bad weather sets in.

While frontlines in Ukraine may become more static due to weather conditions in the next few months than they have been in recent weeks, that does not mean offensive operations will stop completely.

"I expect that Ukraine will continue to do everything it can throughout the winter to regain its territory and to be effective on the battlefield," United States Defense Secretary Lloyd Austin told journalists in Brussels last week, while acknowledging that "winter always presents a challenge when it comes to fighting."

Troops will struggle to stay warm, both vehicles and weapons will be more difficult to maintain and operate, and snow can make it more difficult to detect landmines, among other problems.

Michael O'Hanlon, a senior fellow at the Brookings Institution, said it is difficult "living in the field, doing equipment maintenance in the field, and keeping vehicles running when temperatures get low."

Mark Cancian, a retired US Marine Corps officer who is a senior adviser at the Center for Strategic and International Studies, said the fighting may increasingly focus on villages because of the shelter they provide to whoever controls them.

Ukraine has an advantage in terms of the supplies it is receiving from the North Atlantic Treaty Organization and other countries, which include cold weather equipment, while Russia has struggled with significant logistical problems in the course of the war.