Based off of the information that I have found, there is nothing to suggest that Biden is prioritizing Ukraine over East Palestine.
As explained by the articles, it is true that Biden is not currently visiting East Palestine, but he has worked actively in order to help solve the issue and help the people in the surrounding area.
An article by CNN cites Biden's statements, stating, "'At this point, I'm not,' Biden said, when asked if he has any plans to visit the community, pointing instead to his and his administration's early and consistent response to the disaster.".
Biden was also cited to say, "'You know, we were there two hours after the train went down – two hours, I’ve spoken with every single major figure in both Pennsylvania and in Ohio, and so the idea that we’re not engaged is just simply not there. And initially, there was not a request for me to go out even before I was heading over to Kyiv, so I’m keeping very close tabs on it. We’re doing all we can.'”
Another article by NPR has explained the situation further. It seems as though while Biden himself has not traveled there directly, many different people from his administration have. Pete Buttigieg, his secretary of transportation, multiple Environmental Protection Agency teams along with the EPA's administrator, Michael Regan, and teams from the Federal Emergency Management Agency have been dispatched to the area and have acted on behalf of Biden and his administration.
NPR states, "The White House has previously noted that included teams from the Environmental Protection Agency and the Federal Emergency Management Agency, who were coordinating with local agencies and first responders and that the president was in communication with Ohio Gov. Mike DeWine and neighboring Pennsylvania Gov. Josh Shapiro."
Based off this evidence, the claim that Biden is prioritizing Ukraine over Ohio is false. While it may be true that Biden has not and is not planning on visiting East Palestine and the cite of the train crash, the claim is still not true. Biden has made continual efforts to alleviate the issue by proxy of government agencies and other officials.
https://www.npr.org/2023/02/25/1159382554/in-east-palestine-who-shows-up-isnt-necessarily-a-sign-of-whos-helping
https://www.cnn.com/2023/02/24/politics/joe-biden-east-palestine/index.html