Following shakedown out of San Diego, California, "Sederstrom", a unit of Escort Division (CortDiv) 31, commenced her escort career with a convoy run to Pearl Harbor. Arriving on 1 December, she participated in further training exercises and conducted inter-island escort runs for most of the month; then, on the 24th, the new destroyer escort got underway for the Gilberts as a unit of TU 16.25.9. Three days later, she was diverted to Funafuti, whence she escorted an AK (Navy cargo ship) and an LCT (Landing craft tank) as they delivered cargo to various islands in the Ellice Islands group. In mid-January 1944, she proceeded to Samoa for a run to the Wallis Islands after which she escorted merchant ships into the Gilberts. On 4 February, she delivered her charges to Makin; and, on the 5th, she departed for the Marshalls. From the 7th to the 25th, she patrolled the approaches to Kwajalein lagoon; then screened the transport, , back to the Gilberts and Hawaii.