Iraqi leaders should agree in the next few days on filling key security posts for the government, Secretary of State Condoleezza Rice said Sunday, calling on the United States to be more patient despite growing sectarian violence.

"Of course, they need to get this settled, but they will get it settled," said Rice, predicting it will be in the next week. "The more important thing here is that they get it right. When they get it right, and they will get it right, everybody will forget how long it took them."

An Iraqi parliament session was postponed earlier Sunday after Prime Minister Nouri al-Maliki again failed to reach consensus on candidates to head ministries that run Iraq's military and police. Meanwhile, gunmen dragged passengers off minibuses near Baghdad and killed 21 people in one of Iraq's worst sectarian violence in recent weeks.

But Rice, speaking on three Sunday talk shows, said she had faith that al-Maliki was a strong leader who will be able to assert control. Filling the security posts is a key step for al-Maliki's plan for Iraqi forces to take control of security from U.S.-led troops in 18 months.

"It's only been a matter of a few weeks since you've had a government in place. Let's give the government a little chance now to get settled in and to really begin to work on this situation," she said.

"He has declared a state of emergency in Basra to deal with the situation there," Rice added. "This is a government that is more confident, that has a real basis for action because it is a national unity government."

Sen. Lindsey Graham, a member of the Senate Armed Services Committee, said he believed the recent turmoil in Iraq represents both good and bad news for the United States.

"Every time there's political success in bringing the country together to live as one under democracy, the terrorists ratchet it up because the stakes are high," said Graham, R-S.C., on "FOX News Sunday."

"So the defense minister and the interior minister are hard choices, because they control weapons," he said. "They control the police force. They control the army. And right now the groups within Iraq don't trust each other enough to give the weapons over to an opposing side."

Sen. Carl Levin, the top Democrat on the Senate Armed Services Committee, disagreed. He said Iraq is in turmoil because leaders cannot agree on the key security posts.

"This is a hollow government," said Levin, D-Mich. By prematurely claiming a victory after a new government was formed weeks ago, Bush "was making the same mistake that he made on the aircraft carrier, which was to say, 'Mission accomplished,'" Levin added.

Rice also denied that a decision by U.S. military commanders last week to move about 1,500 combat troops from a reserve force in Kuwait into volatile Anbar province to help establish order in an insurgent hotbed was a sign of growing trouble.

Calling it a move to reinforce the region, she said the United States is simply acting in a support role to Iraqi forces "who are in growing numbers and growing competence."

"As Iraqi forces get better — and they are getting better, they are taking more of the fight — American forces will clearly have fewer responsibilities, and ultimately will come out," Rice said.

Rice appeared on "FOX News Sunday," CBS's "Face the Nation," and CNN's "Late Edition," which also broadcast the interview with Levin.