(Adds Rice comments paragraphs 7-9) By Waleed Ibrahim and Aseel Kami BAGHDAD, Sept 12 (Reuters) - Foreign troop levels in Iraq could drop to less than 100,000 by the end of 2008 if Iraq's own forces were ready and security threats had diminished, Iraq's national security adviser said on Wednesday. Mowaffaq al-Rubaie was speaking after two days of testimony in Washington by the U.S. commander in Iraq, General David Petraeus, who has recommended cutting U.S. forces by about 30,000 by next July because of reduced violence in Iraq. That would bring down U.S. troop numbers to around 130,000, roughly the level before an increase ordered by U.S. President George W. Bush early this year. "Maybe it is not far from the truth if we said that by the end of next year, multinational forces could be less than 100,000," Rubaie told a news conference. "This all depends on the security circumstances and the level of the threat, whether from inside the country or in the region. This also depends on the level of training of the Iraqi forces." He did not talk specifically about U.S. troop numbers -- currently at 168,000 -- but the overwhelming majority of foreign soldiers in Iraq are American. Secretary of State Condoleezza Rice said that, as U.S. troop cuts take effect, "American forces, in lower numbers, (will) turn to other responsibilities", including ensuring Iraq's stability and helping ward off what she called Iranian aggression. "Iraq has very troublesome neighbours. Iran is a very troublesome neighbour," she said, noting Iranian President Mahmoud Ahmadinejad's promise to fill any vacuum left by departing U.S. forces. The United States needed a stable Iraq and other allies in the region "to resist both terrorism and Iranian aggression," Rice said in an interview on NBC's "Today" show. IRAN CONCERNS Iran rejects U.S. accusations it is fomenting instability in Iraq by arming and training Shi'ite militias there and says the U.S. presence is behind the violence. On Wednesday, Tehran said the Petraeus report "will not save America from Iraq's swamp". Asked if the Iraqi government shared U.S. concerns about Iranian involvement in Iraq, Rubaie said both Iran and Syria -- which Washington has accused of allowing insurgents to cross into Iraq -- "know what they should be doing". "We think Iran could help in stabilising the security situation in Iraq, it could give more support to the Iraqi government," Rubaie said. "The Iranians know well what they should do and (what) they are doing in supporting the militias, in smuggling weapons and supporting some extremists." Petraeus said on Monday U.S. force reductions would continue after next summer. But, citing uncertainty over Iran, he said it would be premature to make recommendations now on the pace of such cuts. Such an assessment could be made by March 2008, he said. Rubaie offered no objections to Petraeus' proposed reductions but did not explicitly endorse the plan. He stressed that much depended on how security trends developed. Both the Iraqi and U.S. governments have highlighted the fall in violence under Bush's so-called surge of troops. On Tuesday, Rubaie said all Iraqi army units would be trained and equipped by mid-2008. More than 80 percent of Iraq's army had the capability to take the lead in combat operations, he said, putting total Iraqi security forces at 500,000. Democrats and Bush's Republicans grilled Petraeus on Tuesday in Washington on whether security gains were significant enough to keep U.S. troops in the war zone. Petraeus insisted progress was being made under Bush's strategy of temporarily building up troops to allow time for Iraqi lawmakers to achieve political reconciliation. (Additional reporting by Paul Tait)
