Colombian President Juan Manuel Santos made a "serious mistake" when he characterized Venezuela's socialist "Bolivarian revolution" as self-destructing, embattled Venezuelan leader Nicolás Maduro charged on Wednesday.

Despite Santos "disrespecting the office of the president of Venezuela," Maduro said he remained committed to his offer to meet with his Colombian counterpart in order to address the ongoing border crisis between the two South American neighbors, the Associated Press reported.

Facing criticism over his subdued handling of the spat at home, Santos has begun a diplomatic push to draw attention to the situation and begun issuing harsher statements.

"The (Bolivarian) revolution is self-destructing because of its own effects, not because of the Colombians," he said, referring to the thousands of Colombian nationals who have been targeted for deportation ever since Maduro decreed a state of emergency in western Táchira state.

Caracás also opted to "temporarily" close key checkpoints with Colombia, a situation that now has persisted for three weeks and wrought havoc in the heavily integrated communities along the border, the Wall Street Journal recalled. Some 20,000 Colombians have since returned to their country after being forced to leave by Venezuelan soldiers, according to United Nations estimates.

Maduro's government, meanwhile, tried to match Colombia's public-relations efforts on Wednesday by taking out a full-page ad in the New York Times, seeking to explain its views on the situation.

"Venezuela was forced to take extraordinary constitutional measures by closing sections of the border in order to protect its citizens," the government said in a statement. "Serious threats to our national and economic security have risen in the past few years."

Diosdado Cabello, widely seen as Venezuela's second most powerful politician, meanwhile, insisted that his country would not be "blackmailed by anyone," including Santos.

On Wednesday, Maduro further promised new unilateral measures aimed at guaranteeing safety and stability along Venezuela's borders, the semi-official Telesur television network noted.

"A new stage in the border policy of the Bolivarian revolution has begun," Maduro contended as he announced "open consultation to formulate conditions of a new border of peace."