Donald Trump's attendance at D-Day commemorations in Portsmouth will "take away" from the event, the city's council leader has said.
The president will make a three-day state visit to the UK from 3 to 5 June, Buckingham Palace has announced.
A national event is being held in Portsmouth on 5 June to mark the 75th anniversary of the D-Day landings.
Council leader Gerald Vernon-Jackson said it would now be disrupted by security and protestors.
'Veterans pushed out'
The council has planned for up to 70,000 people to attend the event in Portsmouth.
"Inevitably if Donald Trump is in town there will be controversy, there will be protests, and... veterans will be pushed out from the coverage," Liberal Democrat Mr Vernon-Jackson said.
"It would have been an open access event on the common. Now it will all be behind steel barriers."
The city was the departure point for much of the D-Day landing force in 1944.
Donna Jones, leader of Portsmouth's Conservative group, said Mr Trump's presence would "change the dynamics of the day considerably".
However, she expects most veterans will welcome the US President's presence at the commemoration.
"Having Donald Trump there for the vast majority of those veterans will make it a spectacular event," she said.
"I think it will make them feel very special that the president... is giving his time to come and remember what they did for their nation."