In addition to what David said, I think it is even more plausible if the US puts a little bit more thought into postwar Korea earlier in the war. If the Americans set up ties with Korean exiles during the war and then go on to recognize the self-proclaimed Provisional Government of Korea living in exile in Chongqing, as Korea, during the war and therefore has a visible interest in the land the Soviets may be persuaded to talk to that regime as well (as they talked to the Chinese nationalists) and seek to guarantee their economic and security interests on the peninsula without setting up a Communist government. While Korea certainly was an area Russia had interest in, and in Europe and Iran the Soviets clamped down hard to control their sphere in Europe (but not Iran), I think a consistent expression of US interest in Korea's future and treating Korea as a provisionally recognized actor rather than a blank slate, could have persuaded Stalin to tread with more caution at the end of the war. Their military intervention there at the end of the war might not be as extensive, and they may mainly go in to loot the place and maybe win some economic and security concessions in the northeast, like they did in Manchuria. The noncommunist Koreans are probably not going to be rabidly anti-Soviet if the Soviets are trying to negotiate with them but recognizing their primacy and not trying to set up a Communist administration they totally control in the north.
Kim Gu was the head of the Chongqing exile regime.