North Korean leader Kim Jong Il rallied with his top army commanders, the country's official media reported, amid growing concern the isolated communist regime may conduct its first nuclear test, the Associated Press reported. Japan's vice foreign minister said the test could come as early as this weekend, the anniversary of Kim's appointment as head of the Korean Workers' Party in 1997. Japan said it was stepping up monitoring of North Korea. Kim's meeting was the reclusive leader's first reported public appearance in three weeks and his first since Tuesday when his government shocked the world and alarmed its neighbors by announcing plans to test a nuclear weapon. Kim congratulated the battalion commanders and political instructors for "bolstering the Korean People's Army as invincible revolutionary armed forces," the country's official Korean Central News Agency, KCNA, reported late Thursday. Kim also urged them to "further strengthen the battalions," KCNA said.