US Democratic presidential candidate Joe Biden has criticised Donald Trump's handling of the coronavirus pandemic while courting elderly voters in the battleground state of Florida.
To the president "you're expendable", Mr Biden said at a senior centre in the city of Pembroke Pines.
It came a day after Mr Trump returned to the campaign trail for the first time since his coronavirus diagnosis with a rally in the state.
He told supporters he felt "powerful".
Battleground states like Florida and Ohio are crucial for gathering the 270 electoral college votes needed to win the presidential election, which is not determined by a simple count of votes nationwide.
Opinion polls suggest Mr Biden has a 10-point lead over Mr Trump nationally, but his lead in some key states is narrower. In Florida, the Democrat is 3.7 percentage points ahead, according to an average of polls collated by Real Clear Politics.
Mr Trump narrowly won Florida in the 2016 election in a result buoyed by senior voters. But the latest polls suggest a shift away from the Republican among older voters there this time around.
What did Biden say?
Mr Biden spoke to a group of people at the senior centre in southern Florida on Tuesday, with social distancing measures in place.
The campaign event was in stark contrast to the president's rally the previous day, where thousands attended, many not wearing masks.
Mr Biden accused the president of dismissing the threat that coronavirus posed to senior citizens.
To Mr Trump, "you're expendable, you're forgettable, you're virtually nobody. That's how he sees seniors. That's how he sees you," said Mr Biden.
The "only senior Donald Trump seems to care about" is himself, he added.
Mr Biden also criticised the president for holding "super-spreader parties with Republicans hugging each other without concern of the consequences," while senior citizens couldn't see their grandchildren.
Introducing the Democratic candidate at the event, Florida congresswoman Debbie Wasserman Schultz said it was voters aged 65 or over "who will swing elections in the Sunshine State".
What about President Trump?
At a rally on Tuesday night in the critical election state of Pennsylvania, Mr Trump said his Democratic challenger was "not a nice guy".
"He's a bad guy," the Republican president said of his rival. "He's always been a dummy."
Mr Biden's campaign has made much of his childhood in the state, but Mr Trump told the rally in Johnstown: "They say he was born in Scranton. But he left. He left. He abandoned you. Give me a break."
The president also attempted to woo the key voting demographic of suburban women, many of whom are said in opinion polls to view Mr Trump unfavourably.
"So can I ask you to do me a favour?" the president said. "Suburban women, will you please like me?
"I saved your damn neighbourhood."
Mr Trump held a rally in Florida on Monday and has others planned this week in Iowa, North Carolina, Georgia and Florida again.