WASHINGTON — The US may be able to reduce combat forces in Iraq by next spring, if Iraq’s own security forces continue to grow and improve, a senior American commander said yesterday.He denied reports that the US is arming Sunni insurgent groups to help in the fight against al-Qaida.

Lt. Gen. Raymond Odierno, the top day-to-day commander of US forces in Iraq, did not predict any reductions in US forces but said such redeployments may be feasible by spring. There are currently 156,000 US troops in Iraq.

Speaking to reporters at the Defence Department from his headquarters outside Baghdad, Odierno gave an update on the US offensives under way in Diyala province northeast of Baghdad and in areas south and west of the capital. He said US and Iraqi troops have made important progress.

“I think if everything goes the way it’s going now, there’s a potential that by the spring we will be able to reduce forces, and Iraq security forces could take over,” Odierno said. “It could happen sooner than that. I don’t know.”

He also cautioned that, because the insurgents in Iraq have proven so resilient and adaptive, making any prediction is risky. “There’s so many things that could happen between now and then,” he said, referring to next spring.

Odierno also said it’s too early to say how long the recent addition of almost 30,000 US troops should be maintained. The overall US commander in Iraq, Gen. David Petraeus, is due to report to Washington in September on what the troop buildup is accomplishing, and he has said he intends also to recommend a way forward.

Odierno said murders in Baghdad this week were down to 33, compared with 93 during the second week in January — before the start of a Baghdad security operation that prompted the American troop buildup. He reported that troops have found 128 weapons caches in June, compared with 25 in June of last year.

According to an Associated Press count, at least 230 Iraqis were killed in Baghdad over the past seven days, including murder victims. Police reported finding 121 bodies in the capital; 87 people were killed in the truck bombing of the Shiite Khillani mosque in central Baghdad, and at least 22 people were killed in other ways, including gunfire and roadside bombings.

Odierno said the massive week-old series of operations in and around Baghdad would continue through the summer.

“We have already begun attacking the enemy from multiple directions in a way that I believe he will not be able to resist,” he said of the new offensive aimed at defeating al-Qaida insurgents and extremists, cleaning out their safe havens.

Odierno also said that while coalition forces are co-operating with some Sunni militants, they are not arming them — something observers caution could come back to haunt US troops later.