By Missy Ryan and Will Dunham
WASHINGTON, Aug 10 (Reuters) - The United States conducted a new round of air strikes on Sunday against Islamic State militants in Iraq while congressional Republicans slammed President Barack Obama's intervention as ineffective and called for more aggressive military steps.
Republican Representative Peter King of New York criticized Obama for insisting he will not send U.S. ground troops to combat Islamic State forces in Iraq, adding that the United States has been too timid in the crisis so far.
"We should take nothing off the table. We (should) start off with massive air attacks," King, a member of the House of Representatives Homeland Security Committee, told NBC'S "Meet the Press" program.
"I think doing them from aircraft carriers is limiting them. We should use bases in the area so we can have much more sustained air attacks. We should be aggressively arming the Kurds," King added.
Obama last week launched a campaign of U.S. air strikes and humanitarian air drops in northern Iraq, where militants are threatening religious minorities and encroaching on Arbil, the capital of Iraq's semi-autonomous Kurdish region. Islamic State forces have captured parts of northern Iraq since June.
The moves are the first direct U.S. military action in Iraq since Obama wound down the war and pulled U.S. troops out in 2011.
The United States conducted new air strikes on Islamic State targets near Arbil, the U.S. military said on Sunday. Arbil is the site of a U.S. consulate and a U.S.-Iraqi joint military operations center.
The strikes, launched by drone aircraft and U.S. fighter jets, were aimed at protecting Kurdish Peshmerga forces as they face off against Islamist militants near Arbil, the U.S. military's Central Command said.
It said U.S. aircraft struck and destroyed an Islamic State armed truck that was firing on Kurdish forces near Arbil. Four other strikes followed on armed trucks and a mortar position.
Senator John McCain of Arizona, a leading Republican voice on foreign policy, called for air strikes not only in Iraq but in Syria against Islamic State forces. "They have erased the boundaries between Iraq and Syria," McCain told the CNN program "State of the Union."
McCain said he would be providing "as much training and equipment as I can" to the Kurds and rushing equipment to Arbil.
"This is turning into - as we predicted for a long time - a regional conflict which does pose a threat to the security of the United States of America," said McCain, calling Obama's response to the Iraqi crisis "clearly very, very ineffective, to say the least."
McCain said Islamic State militants have attracted "young men from around the world" to fight on their side, with the movement "metasticizing" throughout the region.
Appearing on the program "Fox News Sunday," Senator Lindsey Graham of South Carolina, another prominent Republican critic of Obama's foreign policy, said, "His responsibility as president is to defend this nation. If he does not go on the offensive against (Islamic State forces) ... they are coming here."
"I am saying that Iraq and Syria combined represent a direct threat to our homeland," Graham said, calling for "a sustained air campaign in Syria and Iraq."
Obama said on Saturday there is no quick fix for the crisis that threatens to tear apart Iraq, where U.S. forces invaded in 2003 in a war launched by his predecessor, George W. Bush.
U.S. military aircraft have dropped relief supplies to tens of thousands of Yazidis who have gathered on Mount Sinjar, seeking shelter from the insurgents.
Senator Richard Durbin, the second-ranking Senate Democrat, said the United States should be trying to prevent genocide in Iraq while also helping Kurds protect their capital. But he said ultimately the Iraqi government should provide security for its people, and that the United States should not step up its use of military force.
"Only Iraq can save Iraq," Durbin said on "Meet the Press," adding it would be "a challenge" to get Congress to back more than limited military strikes.
On "Fox News Sunday," Maryland's Ben Cardin, a member of the Senate Foreign Relations Committee, also backed Obama, saying, "We are not going to get in the middle of a civil war and use (the) American military where it should Iraqis taking care of their own needs." (Additional reporting by Jason Lange and Patrick Rucker; Editing by Frances Kerry)