Ukrainian President Volodymyr Zelensky warned on Friday that Russia has concentrated as many as 100,000 soldiers on the approaches to Pokrovsk, a logistically important city in the Donetsk region. He said the build-up represents the most pressing threat on the front and indicated that Moscow appears to be preparing fresh offensive operations. Separately, an estimate reported by U.S. media put the number of Cuban mercenaries and soldiers fighting alongside Russian forces at around 7,000, highlighting the widening international dimension of the 30-month-old conflict.