President Donald Trump has hailed his operation in Venezuela as a victory, praising the “spectacular assault” that led to the successful capture of former President Nicolás Maduro and his wife, . However, while the Trump Administration celebrates what it deems a win, others have raised serious concerns about the manner in which the U.S. conducted its assault.

The United Nations on Tuesday stated that the U.S. action has made “.” This follows significant criticism from world leaders regarding the Venezuela operation. Furthermore, since Saturday’s pre-dawn raid in Caracas, Trump has threatened that the U.S. may carry out elsewhere in the world, prompting further concern and .

Within the U.S., calls for the President’s impeachment are now gaining momentum, as some Democratic lawmakers and prominent political figures demand that action be taken.

Rep. April McClain Delaney of Maryland on Monday called for the Democratic Caucus to “imminently consider impeachment proceedings” against Trump in response to his military action in Venezuela.

“Over the weekend, we saw the President—without authorization or approval from Congress, as required by our Constitution—launch an attack on Venezuela and voice his intention to ‘run’ the country,” , who criticized her Republican colleagues, accusing them of “allowing Trump to defy the rule of law.”

Urging a response from Congress, Delaney added: “It is time—full stop—for Congress to step up and halt this Administration’s unauthorized and harmful actions.”

This was just the latest serious call for impeachment, as many Democratic lawmakers have labeled Trump’s actions in Venezuela an “impeachable” matter.

Calls for Trump’s impeachment gather momentum

California state Sen. Scott Wiener, , has called for Trump to be impeached over what he refers to as the “illegal invasion and coup in Venezuela.”

“Trump illegally invaded Venezuela, seizing and bombing the capitol, seizing the country’s oil assets, and taking President Maduro and his wife prisoner,” said Weiner in issued on Jan. 3.

“Trump has no legal authority to invade Venezuela, given the lack of authorization by Congress. This lawless act is yet another impeachable offense by this thug President,” claimed Wiener, who cited concerns that the President’s actions could prompt “China to invade Taiwan and Russia to escalate its conquest in Ukraine.”

Rep. Delia C. Ramirez of Illinois Maduro’s capture as a “kidnapping” and insisted the operation was “illegal” and amounted to “dangerous violations of international and U.S. law.”

“Trump and his Administration are out of control because they believe they are untouchable. But they are not… Trump must be impeached,” said Ramirez, who called for the , submitted by Rep. Ilhan Omar last September, to be passed.

, which calls “to direct the removal of United States Armed Forces from hostilities that have not been authorized by Congress,” was referred to the House Committee on Foreign Affairs after its submission and is still awaiting a hearing. 

Rep. Dan Goldman of New York of using the same “illegal and unconstitutional tactics as Maduro” in the operation, saying that such action “not only undermines our democracy and violates our Constitution but also emboldens dictators around the world.”

“I believe President Trump’s true motivation is to take control of Venezuela’s vast oil resources as a favor to American oil executives who helped get him elected,” alleged Goldman, who referred to the operation as a “violation of the United States Constitution” that amounts to “an impeachable offense.”

Rep. Maxime Waters of California, who is also co-chair of the Congressional Caribbean Caucus, that Trump had no authority “to bypass Congress to launch military strikes against a sovereign nation, while brazenly admitting that controlling Venezuela’s oil is part of his motivation.”

“Many Democrats have understandably questioned whether impeachment is possible again under the current political reality. I am reconsidering that view,” said Waters in reference to previous attempts to impeach Trump during his first term as President.

TIME has reached out to the White House for comment.

When has Trump previously faced impeachment?

In December 2019, when he was of leveraging foreign assistance to Ukraine in order to coerce the country’s new Administration to investigate Joe Biden, who at the time was the former Vice President.

The House of Representatives mostly along party lines to impeach the President, sending the case to the Senate. Trump was ultimately by the Senate in February 2020.

A year later, the President was for a second time in a historic House vote. He was accused of provoking violent protestors to storm the Capitol building during the Jan. 6 riots. The Senate once again acquitted Trump, falling short of the 67 majority vote needed, with only voting in favor of the impeachment.