WASHINGTON - US Secretary of State Condoleezza Rice has said the emergence of rival Palestinian security forces was a "dangerous situation" that she hoped President Mahmoud Abbas could resolve.

In a challenge to Abbas, the new Hamas-led government has put its owned armed forces onto the streets. The president, whose Fatah party lost to the militant group in elections last January, responded by ordering the deployment of thousands of Palestinian police in the Gaza Strip.

"It's a very tense situation and one that we hope will be resolved. We obviously believe that President Abbas, who we believe has the confidence of the Palestinian people, should be able to exercise his responsibilities as president of the country," Rice said.

The parade of rival security forces is the latest chapter in a power struggle between Abbas and Prime Minister Ismail Haniyeh, whose militant Hamas movement took power in March.

The United States is leading a campaign to isolate Hamas both financially and politically and has put its support behind Abbas.

Rice said Abbas had frequently spoken about the need for "one authority and one gun" and she said there could never be a stable environment where multiple militias and security forces were allowed to operate.

"So yes, it's a very dangerous situation and it is also the case that a lot of innocent Palestinians are being caught in the violence and criminality that continues to be a problem in the Palestinian territories," Rice said.

Without indicating whether she was referring to Hamas or to Abbas, she added: "The Palestinian leadership has every obligation to control it."