Many outside experts say that Trump's July 25 call with Ukrainian President Volodymyr Zelensky was highly unusual. Trump appeared to have no agenda except to ask for the Ukrainian government to work with his private attorney to investigate a potential 2020 presidential rival and also investigate debunked conspiracy theories about possible interference by Ukraine in the 2016 election. (Sometimes Trump claims he was calling Zelensky to congratulate him on his victory but he had already done that in April.) Trump made about eight requests for help with some sort of investigation involving either former vice president Joe Biden or the Democrats. Just before the call took place, Trump with no explanation halted the expected delivery of military aid. Some U.S. diplomats believed the halt was connected to the president's demands for a probe of Biden, text messages released by Congress show. Moreover, The Washington Post reported that at least four national security officials were so alarmed by Trump’s ongoing pressure campaign on Ukraine that they lodged objections with a White House lawyer before and right after the call.