More than one million people have left Venezuela to live in neighbouring Columbia, as the worst economic crisis in the socialist country’s history continues to deepen.
Mr Santos, who was replaced by conservative Ivan Duque earlier this week, told the French daily Le Figaro that the Venezuela crisis was one of Columbia’s biggest challenges.
“It is undoubtedly the most serious problem we face. We have taken in more than one million Venezuelans fleeing this very deep crisis, which is the result of a regime that has destroyed democracy and violated all human rights,” Mr Santos said.
“We took a very critical stance against the Maduro regime and refused to recognise the results of the May presidential election. There is no more democracy, no more freedom and no more respect for human rights left in Venezuela,” he continued.
Mr Santos added that it was “inconceivable” that people were “dying from hunger and lack of medicines” in the oil-rich country, once Latin America’s wealthiest.
Widely blamed for the unprecedented crisis, Mr Maduro has refused to make reforms to the state-led economy, such as overhauling dysfunctional currency and price controls, despite pressure from political opponents and protesters.
The leftist leader has instead blamed the country’s hardships on a US-led “economic war”.
Relations between Venezuela and Columbia further soured this week after Caracas said that Mr Santos was behind a failed assassination attempt on Mr Maduro.
Mr Maduro was giving a speech to mark the 81st anniversary of the national army on Saturday when drones loaded with explosives went off near the president’s stand, Venezuela’s Communications Minister Jorge Rodriguez said.
“Everything points” to a right-wing plot linked to Columbia and the US state of Florida – where many Venezuelan exiles live – Mr Maduro said in a national address, adding that he had “no doubt” Mr Santos was “behind the attack”.
The Columbian government has denied any involvement in the drone attack, saying there is “no basis” to Mr Maduro’s allegations.
It remains unclear who helped orchestrate the failed assassination attempt.
On Tuesday, a little known group called Soldiers in T-shirts claimed responsibility for the attack on social media, saying it had planned to fly the drones at Mr Maduro but that they had been shot down by the military.
The group is yet to respond to media requests for comments.
On Wednesday, however, the pro-Maduro Supreme Court said that opposition leader Julio Borges, the former president of congress, was involved in the attack and ordered his arrest.