Senate Minority Leader Mitch McConnell (R-Ky.) weighed in Monday on the U.S. intervention in Libya, hours before President Obama is set to deliver an address on the crisis at 7:30 p.m. EST.

McConnell had not issued a formal statement on Libya since the United States became involved in the crisis earlier this month. But he blasted the president in remarks on the Senate floor for not clarifying U.S. strategy and for not formally consulting Congress on the action.

“If the American people are uncertain as to our military objectives in Libya, it’s with good cause,” McConnell said in remarks on the Senate floor. “The president has failed to explain ... what follows the evident establishment of a no-fly zone over Libya, as it was originally described. Further, the President has articulated a wider political objective of regime change in Libya that is not the stated objective of our military intervention; nor is it the mandate of the UN resolution that the president has used as a justification for our military efforts there.”

McConnell said he would be listening for answers from Obama to four questions -- duration and cost of the U.S. intervention; the justification for risking the lives of U.S. service members; and America’s role in Libya’s civil war.

He also criticized the administration for taking action on Libya “without adequate consultation with Congress or sufficient explanation to the American people,” and called on Obama to reiterate his pledge that U.S. combat forces’ role would be “limited in scope and duration” – or else Obama should ask Congress for its formal backing.

New Jersey’s Sen. Robert Menendez (D) meanwhile, also issued a critique of Obama’s handling of Libya. Menendez, a member of the Senate Foreign Relations Committee who has been an outspoken critic of Libyan leader Moammar Gaddafi, called on Obama to remind Americans of Gaddafi’s alleged role in ordering the 1988 bombing of Pan Am flight 103.

“Qaddafi is a terrorist – the moral equivalent of Osama bin Laden – a man who ordered the bombing of Pan Am Flight 103, which killed 270, including 34 New Jerseyans, and who in 2009 swapped a lucrative oil deal in exchange for the release of the convicted Pan Am bomber,” Menendez said in a statement.

He added that “ Qaddafi will continue to support terrorism and, therefore, continue to threaten Americans at home and abroad. That is why a Libyan no fly zone is not only in the interest of the international community, but is also in the national security interest of the United States.”

Concern about Congress’s role in approving the military deployment also ran bipartisan. Echoing McConnell, Rep. Dennis Kucinich (D-Ohio) said in a statement that the president “bought a new war for the American people without Congressional approval.”

“We must know what it will cost, how long it will last, what is the end game, and when will NATO -- whose military bills we pay -- get out,” said Kucinich, who has offered an amendment on defunding the U.S. involvement in Libya. “President Obama’s failure to come to Congress, as required by the Constitution, left us without the opportunity to have a full and ample debate on the merits of military intervention in Libya.”

The lawmakers’ remarks underscore the mixed reaction from Capitol Hill on the president’s actions in the Libyan crisis. House Speaker John Boehner (R-Ohio) has also outlined questions about the mission that Obama has not yet answered, while other Republicans, such as Sen. John McCain (Ariz.), have criticized the administration as being too slow to act on the crisis.

At the same time, some Senate Democrats, including Sens. Carl Levin (Mich.) and Dick Durbin (Ill.), have strongly defended the president’s efforts. Yet some of the administration’s harshest critics on the intervention in Libya have been members of his own party, especially in the House, where lawmakers have objected to a decision-making process that they argue has left Congress out of the loop.

That means that whatever Obama says in his address Monday night, he is likely to satisfy only some members of Congress on both sides of the aisle.