Congressional hawks cheered President Barack Obama’s call on Thursday for Syrian President Bashar Assad to resign, a move that many of those Members have urged the administration to take over the last several months.

Sens. John McCain (R-Ariz.), Lindsey Graham (R-S.C.) and Joe Lieberman (I-Conn.) said Obama’s announcement marked “a position we have long argued should be the policy of the United States.”

“Assad has been given every last chance to respond to the peaceful demands of the Syrian people for change, and he has squandered them all,” the trio said in a joint statement. “Instead he has shown that he is wedded to the path of violence, trying to remain in power by slaughtering civilian protesters. It is critical that Assad not be allowed to prevail.”

Obama also revealed that the United States would impose a new round of sanctions against the Middle Eastern country.

House Majority Leader Eric Cantor praised Obama and called Syria “a proxy for Iran.”

“Under the Assad regime, Syria has been a proxy for Iran, a supporter of terror, and a threat to United States interests and our allies in the region,” the Virginia Republican, who was on a Congressional trip in Israel on Thursday, said in a statement. “The recent atrocities and Assad’s brutalization of his own people in Syria are extremely alarming and reflect a long history of anti-American hostility, and I join President Obama in calling for Mr. Assad’s resignation.”

The announcement follows months of violent unrest in Syria, where citizens have been protesting the Assad regime. A senior White House official told reporters on a phone call Thursday that “we have consistently said that President Assad must lead a democratic transition or get out of the way.” Obama’s announcement marked his most serious efforts to help bring that transition to pass in the troubled country, according to the official.

“We have steadily ratcheted up our pressure on the Syrian regime over the course of the last several months,” the official said, noting that Obama began stepping up his rhetoric in May.

The official also pointed to the president’s alliance with key European allies in his latest effort to soothe unrest in Syria and bring about a democratic transition. The top leaders in Canada, France, the United Kingdom and Germany voiced their support for Obama’s latest efforts, which also drew support from the European Union.

White House officials on the reporters’ call would not rule out the use of military force, but one acknowledged, “I don’t think anybody believes that that is the desired course in Syria.”

Obama caught criticism from Congress for not reacting quickly enough to unrest in Libya, where dictator Moammar Gadhafi came under fire for attacking unarmed civilians and protesters. The United States ultimately joined a NATO-led campaign in the North African country that began in March, but Members complained that the White House did not consult Congress on the matter or seek approval under the War Powers Act.

In regard to Syria, Lieberman penned an opinion piece this month suggesting that the president “finally say unequivocally that Assad must go.”

“The administration should also redouble efforts to persuade key countries and companies to ratchet up the pressure on Assad — in particular by sanctioning the Syrian energy sector and by seeking tough action at the United Nations Security Council,” Lieberman wrote in the Wall Street Journal. “A binding resolution condemning the regime’s human rights abuses and imposing sanctions directly on Assad and his lieutenants is now critical.”

A group of 66 Senators sent a letter to Obama two weeks ago calling on him to impose harsher sanctions against Syria. Sen. Barbara Boxer (D-Calif.), who helped lead that campaign, said Obama’s announcement Thursday adequately fulfills the priorities outlined in that letter.

“For weeks, we have watched the Syrian people endure horrific violence, including the indiscriminate massacre of civilians,” she said in a statement. “Today’s actions by President Obama send an unequivocal message that the regime’s tactics have repulsed the entire world.”