From announcement to cancellation, why was the meeting between Trump and Putin "suddenly put on hold"?

Jin10 data reported on October 23, local time on October 22, U.S. President Trump stated that he believes it is “inappropriate” to meet with Russian President Putin now, thus canceling the meeting with Putin in Budapest. Analysts believe that Trump's statement already implies the answer to why the meeting was postponed. Within a few days, Trump faced dual refusals from both Russia and Ukraine. Clearly, under the premise that both Russia and Ukraine insist on their respective positions and there are no guarantees of results, Trump believes that both sides are not ready to negotiate seriously, and that the current meeting is a “waste of time.” Analysts say that to end the Russia-Ukraine conflict, the U.S. cannot do without support from Europe. If the U.S. and Europe cannot maintain unity on the Ukraine issue, it will be difficult to resolve the Ukraine conflict through diplomatic means, which has become a consensus among the U.S. and Europe.