Published: May 27, 2010 5:59 PM EDT
Updated: May 27, 2010 3:59 PM EDT

WASHINGTON (AP) - President Barack Obama says federal regulators under his watch should have shown a "greater sense of urgency" about tightening oversight of oil and gas.

Obama says a moratorium on new deepwater oil wells is the first of many steps that will be taken to improve oversight of the industry. He credits Interior Secretary Ken Salazar for many reforms, but says "more needs to be done."

Obama says some proposed drilling lease sales off the coasts of Alaska and Virginia and the Gulf Coast will be delayed or canceled.

At a news conference Thursday, he decried what he called a "scandalously close relationship" between regulators and oil companies and said that must be stopped. He said he has confidence Salazar can do that.

Obama: Gov't in charge of oil disaster response

President Obama moved aggressively to show his government is in charge of the Gulf oil spill on Thursday, calling the spill an "unprecedented disaster" and blasting a "scandalously close relationship" between oil companies and regulators.

"The American people should know that from the moment this disaster began, the federal government has been in charge of the response effort," Obama told a news conference. He was responding to criticism that his administration had been slow to act and had left BP in charge of plugging the leak.

Obama said many critics failed to realize "this has been our highest priority." He conceded that "people are going to be frustrated until it stops."

Obama announced a series of new steps to deal with the aftermath of the spill, including continuing a moratorium on drilling permits for six months. He also said he was suspending planned exploration drilling off the coasts of Alaska and Virginia and on 33 wells currently being drilled in the Gulf of Mexico.

The president, speaking to reporters in the East Room of the White House, spoke as oil giant BP pumped mudlike heavy drilling oil into the well in hopes of stopping the flow. He said while the "top kill" procedure was an example of his administration's willingness to try "any reasonable strategy" to stop the gusher, the process "offers no guarantee of success."

Over and over, the president sought to counter criticism that the administration was giving too much leeway to BP. "Make no mistake, BP is operating at our direction," he said. "We will demand they pay every dime they owe for the damage they've done and the painful losses they've caused," Obama said.

He denounced what he called "the oil industry's cozy and sometimes corrupt" ties with government regulators. He spoke shortly after the head of the troubled agency that oversees offshore drilling resigned under pressure.

The departure of Minerals Management Service Director Elizabeth Birnbaum was announced just before Obama's news conference began. Asked about inevitable comparisons between his administration's handling of the disaster with his predecessor's handling of Hurricane Katrina in 2005, Obama said: "I'll leave it to you guys to make those comparisons...What I'm thinking about is how do you solve the problem?"

"I'm confident people are going to look back and say this administration was on top of what was an unprecedented crisis," he added. Still, he acknowledged, "We've got to get it right." Obama's insistence that his administration was in charge of dealing with the disaster were a marked change in language.

Previously, administration officials had emphasized that while they were overseeing BP's actions, the oil company had the expertise and equipment to do the job. As an example of the government's hands-on approach, Obama said that BP had wanted to drill a single "relief" well in an effort to eventually stop the leak in several months if all else failed. Instead, the administration insisted on two relief wells being drilled, Obama said.

Sen. Frank Lautenberg , D-N.J., a critic of offshore drilling, said Obama took an important step to halt the most imminent environmental threat to the Atlantic coast, but he said the danger will remain until there is a permanent ban on drilling in the Atlantic.

"BP's oil catastrophe in the Gulf is a wake-up call for our nation. Giving Big Oil more access to our nation's waters will only lead to more pollution, more lost jobs and more damage to our economy," Lautenberg said.