The assembly, which has wide-ranging powers and is expected to rewrite the Venezuelan Constitution at President Nicolás Maduro's behest, also has prohibited Ortega from leaving the country and has frozen her assets.
Venezuela's newly-installed constitutional assembly has voted unanimously to remove chief prosecutor Luisa Ortega and replaced her with a government loyalist.
Earlier in the day, the Constituent Assembly replaced former Attorney General Luiza Ortega Diaz, known for her disagreement with the actions of the country's authorities, with Venezuela's Human Rights Ombudsman Tarek William Saab.
Members of the all-powerful constitutional assembly had pledged in their first meeting to move quickly against Mr Maduro's opponents. "Tomorrow we start to act".
Members of the Constituent Assembly had announced they would fire Ortega the first chance they got.
The assembly will have powers that supersede all other branches of government, and the opposition fears it will be used as a tool to strengthen Maduro's power and crack down further on his political opponents. Supporters say it will pacify a country rocked by violent protests.
At least 120 people have died and hundreds more have been jailed in Venezuela's four-month crisis.
Several opposition activists have been jailed in recent days, others are rumoured to be seeking exile and one leader has broken ranks from the opposition alliance to say his party will field candidates in regional elections despite widespread distrust of the electoral system. The announcement was made during a meeting in Sao Paolo, Brazil to discuss political turmoil between the Venezuelan government and the right-wing opposition.
Teen detained after jumping from plane at San Francisco International Airport
In his statement , Yakel mentioned that no other flights or runaways had been affected and the boy was not injured too. The teen, a USA citizen, was accosted by an airfield construction crew and is now in police custody.
McMaster cites the historical resentment in Latin America over the long history of US military interventions in the region.
Earlier, she denounced what she called a military "siege" on Twitter, publishing photos apparently taken from security cameras showing about 30 national guardsmen in riot gear standing outside her headquarters.
"You've seen Maduro have some lame attempts to try to do that already", McMaster said in an interview on MSNBC that aired Saturday.
Foreign Ministers of the Common Market of the South, Mercosur, have made a decision to apply the "democratic clause" established by the group's Protocol of Ushuaia, suspending Venezuela from the regional bloc.
He added that it's "important for us to place responsibility for this catastrophe on Maduro's shoulders".
At the meeting, Brazilian Foreign Minister Aloysio Nunes said political suspension does not imply neither expulsion nor the application of economic sanctions, since they are not included in the Protocol of Ushuaia.
The constituent assembly could also re-write the constitution, re-arrange state institutions and allow Mr Maduro to rule by decree.