President Ricardo Martinelli has warned Venezuela that its decision to break off relations with Panama should not be used as an excuse to renege on its more than $US1 billion ($A1.1 billion) debt.
"I don't want to think that this is an excuse not to pay and that the Venezuelan state is a deadbeat," he told reporters.
Venezuela on Thursday ordered the expulsion of Panama's ambassador and three other diplomats.
At least 20 people have been killed in more than a month of anti-government protests in Venezuela that President Nicolas Maduro blames on a US-backed "fascist" plot.
Maduro lashed out on Wednesday at Panama, calling it a "lackey" of the United States for seeking a meeting of the Organisation of American States on the turmoil.
But Martinelli suggested that Maduro's real motive was to get out from under huge bills owed to the Colon duty-free zone and to COPA, the Panamanian airline.
"Venezuela would appear to be bankrupt, although it shouldn't be because it is a very rich country," said Martinelli.
It "has no excuse" to not pay off its debts, he added.
The manager of the Colon Free Zone, Leopoldo Benedetti, said Venezuelan importers have about $US2 billion in unpaid bills.
COPA, which Martinelli said is owed $US480 million, issued a statement saying its flights between Panama and Venezuela were operating normally.
