The vessel was assigned to Amphibious Force, Pacific Fleet, and became a member of Transport Division C. For Operation Watchtower, Alchiba's Division served under Task Force 62 (South Pacific Amphibious Force), Task Group 62.1, Transport Group X-Ray. On 22 July, she sailed for Korp Island, Fiji Islands, to participate in amphibious landing exercises — the rehearsal for the first American assault landing in the Pacific theater. Upon completing this training, she embarked marines and filled her holds with ammunition, amphibious tractors, gasoline, and general supplies and got underway for operations in the Solomon Islands. The vessel arrived off Guadalcanal on 7 August, where she disembarked her troops, unloaded her cargo, and helped rescue survivors from the "USS Astoria", sunk after the Battle of Savo Island. She left the Solomons on 9 August, bound for New Caledonia. After her arrival at Nouméa on the 13th, the ship loaded on more cargo and, nine days later, commenced a voyage which took her to Pago Pago, American Samoa; Tongatapu, Tonga Islands; and Espiritu Santo, New Hebrides.