BUDAPEST, April 11 -- US President Donald Trump made a late intervention in Hungary's bitter election campaign yesterday, as nationalist Prime Minister Viktor Orban battles for votes against a pro-European opponent leading him in polls.

Trump vowed to bring US "economic might" to Hungary if Orban's party secures a victory over his arch-rival Peter Magyar in Sunday's election.

The comments added late drama to the campaign finale that saw Orban and Magyar trade accusations of dirty dealing.

Orban, who has run Hungary for 16 years and is close to Trump and Russia's President Vladimir Putin, faces an unprecedented challenge with opinion polls putting Magyar's conservative Tisza party well ahead.

"We are excited to invest in the future pro...