ERIE, Pa. — Democratic vice presidential candidate Tim Kaine offered a systematic takedown of Donald Trump’s business dealings and campaign claims Tuesday, arguing the Republican nominee’s presidential campaign amounts to nothing more than “Trump’s next big con.”

“Donald Trump, thus far, has utterly failed to answer basic questions that Americans voters have a right to know,” Kaine said to a crowd in Erie, Pennsylvania, his first public stop in several days.

Kaine said the Republican presidential nominee isn’t being truthful or open about his financial dealings, taxes, ties to foreign governments and even his medical records. He suggested Trump would not stop Russian aggression in Europe and may be lying about his health, an allegation Trump has thrown at Democratic presidential nominee Hillary Clinton. Kaine went after Trump for nearly 20 minutes, among his most sustained remarks yet on the rival campaign.

“A candidate who’s on the up and up has no problem giving you the facts,” Kaine said.

On Russia, Kaine said Trump has a troubling history of hiring and seeking advice from people who offer favorable views of President Vladimir Putin’s administration. He said Trump’s failure to release his tax returns makes his financial ties to the country unclear.

Trump has praised Putin on several occasions as a strong leader, and his former campaign manager Paul Manafort resigned over his financial ties to Russian allies.

All of this, Kaine said, means Trump would not defend American allies against Russian advances or stop Russian cyberattacks aimed at destabilizing American elections, two significant claims against a would-be commander in chief. Even as he made such serious allegations, Kaine maintained his folksy demeanor, eliciting laughs from the crowd.

“This guy has a weird sense of humor encouraging Russian cyber-attacks against the American political process,” he said, referring to Trump’s call for Russia to find Clinton’s missing emails, a remark he later said was a joke. “Well, that’s just a laugh riot isn’t it?”

On the issue of the candidates’ health, Kaine pointed to recent news reports questioning the validity of the medical report written by Trump’s doctor. Kaine said Trump is trading in fringe conspiracy theories by questioning whether Clinton is in poor health.

“Hillary Clinton is one tough and one healthy person,” he said.