In 1900, he was promoted to captain. In 1902, he was reassigned outside of the present-day Lithuania to the stationed in Rivne in the present-day Ukraine. In July–August 1905, he completed artillery courses for officers in Orenburg and was assigned to the 33rd Infantry Division as the commander of its machine gun company. According to the interwar Lithuanian press, Žukauskas fought in the Russo-Japanese War (specifically, in the Battles of Liaoyang and Shaho), but this is not reflected in surviving service records of Žukauskas.