The strongly worded statement, issued by the Vatican's Secretariat of State, said Pope Francis is following closely the situation in Venezuela, where President Nicolas Maduro accelerated a showdown with the opposition, as he inaugurated his bitterly-opposed new assembly.
The delegates unanimously elected Friday their leader, Delcy Rodriguez, who now has more power than Maduro. She was a longtime supporter of the late President Hugo Chavez but has been critical of Maduro's government and opposed some of its actions.
The national constituent assembly also declared that Ortega Diaz can not leave the country and that her assets have been frozen.
"Do not think we're going to wait weeks, months or years", Rodriguez said during her first speech Friday.
The installation of the all-powerful constitutional assembly is likely to intensify a political crisis that has brought four months of protests that left at least 120 people dead and hundreds jailed.
The foreign ministers of Brazil, Argentina, Uruguay and Paraguay announced Saturday that Mercosur was suspending Venezuela due to a "rupture" with the democratic order. The Vatican also urged Venezuela's security forces to avoid "excessive and disproportionate use of force" in dealing with protesters.
Venezuelan opposition, as well as the European Union and the United States, among other countries, refused to recognize the body's legitimacy.
The constituent assembly will have no checks on its power to re-arrange government institutions.
She also condemned foreign criticism of Venezuela. He has said the country is the victim of an economic war led by the "international right wing" while blaming Venezuela's misfortunes on poor management and rampant corruption.
This week saw the arrest of the nation's two most prominent opposition leaders - they were actually already under house arrest but Tuesday were dragged off to prison.
The election has come under mounting scrutiny since the CEO of an global voting technology company said that "without any doubt" the official voter turnout number had been tampered with - a charge that Maduro and the National Electoral Council have dismissed.
The 545-member constituent assembly is made up entirely of pro-government loyalists after the opposition boycotted the vote as unconstitutional. Two days ago the USA placed him in the Department of the Treasurys Office of Foreign Assets Control as a Specially Designated National, joining another 30-something current and former members of his administration, including his Vice President and the head justice of the Supreme Court.
The constituent assembly replaced Ms Ortega with human rights ombudsman Tarek Saab, a government ally whom the opposition says has turned a blind eye to state abuses. Government intelligence officials said both men were arrested for violating the terms of their house arrests, claiming they planned to flee the country after the elections.
Opposition activists say the government has been ineffectual in addressing the country's most pressing needs amid spiraling inflation, violent streets and scarce food and medicine.