The president put a hold on the money because he didn’t trust the corrupt Ukrainian government with American tax dollars. President Trump has every right to hold money if he doesn’t think the government receiving it is spending it legally.
"Of course I wanted to make sure the Ukraine government took the proper steps regarding corruption investigations. It would be disgraceful to have American taxpayer funds sent to Ukraine in the form of financial assistance, only to have a lot of it end up in the pockets of the Biden family."