There are not many close islands east of Howland Island.
Amelia and Fred had passed by or over the Gilbert's on their way to Howland, so a likely scenario for them when unsuccessful in finding Howland or the USCG cutter Itasca, would have been to turn to the west and seek an alternate spot to land or ditch in friendly (not Japanese held) territory.
If, for some reason, they were actually north of Howland at ETA- turning to the west would have brought them into the Marshall Islands. These were part of a larger group of Pacific islands previously owned by Germany, which were "Mandated" by the League of Nations after WW I and assigned to Japan to administer.
By 1937, Japan considered them to be Japanese owned territory and had begun to fortify them, building runways, radio stations, gun emplacements, ammunition dumps, docks, troop quarters, food storage buildings, water cisterns, etc.
The Imperial Japanese Army and Navy , based on Saipan, ran the area with an iron fist and arrested or detained anyone caught "trespassing".
It is strongly believed by some that Amelia and Fred survived a landing or ditching and were captured by the Japanese.