From the opening words, he told Republicans to be on alert for what he claimed was a Democratic plan to rig the contest.
Opponents say Trump's increasingly extreme resistance to expanded mail-in voting -- a method already used widely in the United States -- is an attempt to suppress voter turnout.
Polls show Trump trailing Democratic candidate Joe Biden, who had his convention last week, as Americans turn on the president's handling of the coronavirus pandemic.
Donald Trump opened his bid for a second term after securing the Republican nomination Monday, with his party launching its national convention as the US president claims Democrats want to "steal" the election that polls currently show him losing.
Minutes after the party completed the nomination vote confirming Trump as the candidate on November 3, he appeared at the convention in Charlotte, North Carolina, to deliver a rambling, often dark speech lasting close to an hour.
