Elements of the 25th IMR saw combat during the Battle of the Visayas and Battle of North Borneo in April and July 1945 respectively. At this time the regiment was one of the main elements of the Thirty-Seventh Army, along with the 56th and 71st Independent Mixed Brigades. The 9th Company resisted the 2nd Battalion of the US Army 163rd Infantry Regiment's landings on small islands off Tawi-Tawi between 2 and 6 April before withdrawing in small boats to the mainland of Borneo. Around 30 Japanese were killed in this fighting, and two Americans were killed and four wounded. After reaching Sandakan, the company began an overland march to re-join the remainder of the regiment, and was at Ranau at the end of the war. The only part of the main body of the 25th IMR's sector to be attacked was Papar. The regiment did not resist the Australian &lt;a href="2/32nd%20Battalion%20%28Australia%29"&gt;2/32nd Battalion's&lt;/a&gt; occupation of Papar on 12 July, with Australian official historian Gavin Long writing that its only defenders were "two Japanese with a machine-gun who made off as the Australians approached". At the end of the war the 25th IMR had a strength of over 900 personnel.