Venezuelan opposition leader Edmundo Gonzalez Urrutia released a statement on Sunday, calling the United States' capture and arrest of President Nicolas Maduro "a turning point in Venezuela's recent history."

"Venezuelans, the events of recent days have marked a turning point in Venezuela's recent history. It is natural that there are mixed feelings, which we understand and respect. This moment is an important step, but it is not enough," he said.

The opposition leader referenced the 2024 election in the country, which he claims to have won, saying those results should be respected. He went on to refer to himself as the president of Venezuela.

"As president of Venezuela, I make a calm and clear appeal to the National Armed Forces and the State Security Forces. Your duty is to comply with and enforce the sovereign mandate expressed on July 28, 2024. As Commander-in-Chief, I remind you that your loyalty is to the Constitution, to the people, and to the Republic," he said.

Secretary of State Marco Rubio, Secretary of Defense Pete Hegseth, Chairman of the Joint Chiefs Dan Caine, CIA Director John Ratcliffe and Attorney General Pam Bondi will be on Capitol Hill on Monday evening to provide a closed briefing to top lawmakers on the actions in Venezuela, multiple sources confirmed to ABC News.

The Gang of 8, which includes the House and Senate majority and minority leaders and the chairs and vice chairs of the House and Senate Intelligence Committee, will receive the briefing as well as the top Republican and Democrat on the Senate Foreign Relations Committee, Senate Armed Services Committee, House Foreign Affairs Committee and House Armed Services Committee.

The briefing is expected to take place at 5:30 p.m.

This comes after Senate Minority Leader Chuck Schumer and House Minority Leader Hakeem Jeffries on Saturday called for the administration to immediately brief the Gang of 8 on Venezuela.

-ABC News' Jay O'Brien, Lauren Peller and Allison Pecorin

The Foreign Minister of Venezuela, Yván Gil, said in a post on Telegram on Sunday that the personal immunity of a sitting head of state has been violated, which constitutes a fundamental principle of international law.

"Whoever kidnaps a president kidnaps the sovereignty of a people," he said.

"The masks have fallen," Gil said. He went on to claim that the United States government is only interested in Venezuela's natural and energy resources.

-ABC News' Will Gretsky

Nicolás Maduro and his wife, Cilia Flores, are both scheduled to make their initial appearances in Manhattan federal court at noon ET on Monday before Judge Alvin Hellerstein.

Like her husband, Flores is in federal custody at MDC-Brooklyn.

It was not immediately clear whether either of them had retained legal counsel ahead of their arraignments.

Maduro and Flores are among six defendants named in a 4-count superseding indictment that accused them of conspiring with violent, dangerous drug traffickers for the last 25 years.

Maduro’s son, two high-ranking Venezuelan officials and an alleged leader of the Tren de Aragua criminal gang are the other defendants.

-ABC News' Katherine Faulders and Aaron Katersky