Trump uses battleship speech to say 97-year-old WWII vet is mentally sharper than Joe Biden

President hits another swing state at event where few were wearing masks

Donald Trump used an official White House event in front of a World War II-era battleship to take a campaign trail dig at Democratic presidential nominee Joe Biden, continuing to raise questions about the former vice president's mental capacities.

The president jetted to Wilmington in North Carolina, among a list of swing states that will decide November's election, to designate the town the first "American World War II Heritage City". He spoke at his presidential lectern in front of the massive Battleship North Carolina, noting how many kills the ship had in the war.

Mr Trump paused several times during his remarks, which he was reading from a binder, to note the thunder overhead. He told the crowd he was going to have to speed up the proceedings due to the bad weather. For once, the president mostly stuck to the script.

But despite the hurried remarks, the always-in-campaign-mode president worked in a jab at his general election foe as the skies rumbled.

"He's 100 per cent sharp," Mr Trump said as he praised a 97-year-old World War II veteran he met prior to the event.

"I know a 78 year old that's not so sharp. But he's 97, and he's 100 per cent because it has nothing to do with that. Seventy-eight's young. It depends who's 78, that's all.

"He's 97. I said, 'Man, you are something," the president said with a smirk, "and physically in great shape."

A big part of the Trump campaign's strategy is to paint the former vice president as too old and mentally lacklustre to perform the duties of the office.

Mr Biden has fired back, saying he is eager to prove the opposite in his three debates against Mr Trump.

Multiple polls for months have shown the two in a virtual dead heat in North Carolina, which Mr Trump won by just under four percentage points in 2016.