That was the strategy that FDR and Churchill agreed to, but the primary person driving it was Stalin, because he didn't want the US and Britain to defeat Japan before he got a chance to attack them, and he knew he would not be able to attack them until Germany was defeated. (He wanted to attack them so he would have a pretext for taking over territory that Russia had lost in the Russo-Japanese war in 1904-1905.) As events proved, the US and Britain did not need any help from the USSR to defeat Japan militarily, and with different diplomatic choices they probably could have gotten Japan to surrender before the USSR attacked.
Once FDR died and Truman took office, btw, it was no longer clear that having the USSR enter the war against Japan was a US objective. Truman, unlike FDR, was not a fan of Stalin and viewed him as a geopolitical threat, not an ally. Which, historically speaking, was a sounder view.
Such as?
https://www.youtube.com/watch?v=Y43-p3xLDyo
This is from the final episode of the series. Easy Company have fought their way from Normandy to Germany, losing hundreds of their friends and brothers in battle after brutal battle. Now the Nazis have surrendered and they finally have some respite - but their celebrations are shortlived. Their commanding officer informs them that they're to be redeployed to the Pacific. The war isn't over, and the expression on Malarkey's face at 2:09 says it all.
Whatever anyone says about the atomic bombings, I bet those men were damn happy to hear about Japan's surrender. Imagine if they'd been sent to invade Japan, in another brutal campaign that would have taken months if not years, costing hundreds of thousands more Allied lives.
Then imagine telling them that the government had secretly developed a powerful new weapon that could have ended the war earlier and avoided all this bloodshed - but they hadn't used it because they were worried about the moral implications. I don't think they'd have agreed it was the right choice.
Japanese knew that Soviet rulers did not care if another million of soldiers died and Soviet occupation was considered much worse outcome. That contributed to their surrender to US.
Even so, a land conquest of Japan would have cost vast numbers of lives - far more than the nukes.
When people die one by one in war, the emotional impact is blunted. But when a million die in one bomb, it seems much worse, even if the overall body count is lower.