AMMAN U.S. Republican presidential candidate John McCain said on Tuesday that a U.S. troop build up in Iraq was succeeding and a premature withdrawal would dramatically enhance Iranian influence in the region.
McCain was speaking in Jordan, where he held talks with King Abdullah, after a visit to Iraq where he met Iraqi leaders and U.S military officials as part of a Senate Armed Services Committee fact-finding mission.
"If we pull out of Iraq ... then obviously the Iranian influence is dramatically increased, al Qaeda has greater influence and endangers the region dramatically, and the United States's image and security challenges are dramatically increased," said McCain.
McCain hopes his Middle East tour will remind Americans of his national security credentials and counter demands by Democratic presidential hopefuls Hillary Clinton and Barack Obama for troops to be withdrawn from Iraq as soon as possible.
The Iraq war is a major issue in the U.S. presidential campaign. As it enters it sixth year, the war has cost the U.S. economy $500 billion and seen nearly 4,000 U.S. soldiers and tens of thousands of Iraqis killed.
McCain, a former Navy pilot and Vietnam War veteran, supported going to war but was a vocal critic of how the war was conducted until an extra 30,000 troops were deployed last year as part of a new counter-insurgency strategy.
"We were very encouraged by our visit to Iraq that the surge is succeeding and in the reduction in U.S. casualties but it is complicated by the Iranian involvement in Iraq... (and) Syrians continue to expedite the flow of foreign fighters in Iraq," McCain added.
Attacks across Iraq have fallen by 60 percent since last June, when the troop build-up was completed. There has been a spike in violence since January, with an upsurge in suicide bombings linked to al Qaeda.
The U.S. military says most of the suicide bombers tend to be foreign fighters.
However McCain, whose political standing has risen and fallen to some degree depending on whether the war has been going well or badly, warned "there was still a long way to go" before defeating al Qaeda.
"The situation has dramatically improved but I also want to emphasise time and again al Qaeda is on the run but they are not defeated," he added.
McCain repeatedly lashed at Iran, accusing it of training terrorists, including al Qaeda, to attack U.S. troops and supporting Lebanon's powerful Shi'ite group Hezbollah .
"I am deeply concerned about Iranian influence not only in Iraq but on nuclear weapons, on sponsorship of Hezbollah and other terrorist organisations," he told reporters.
He said America could not accept a nuclear-armed Iran and backed much tougher financial and trade sanctions against Tehran in coordination with Washington's European allies.
The West accuses Iran of trying to acquire nuclear weapons under cover of a civilian programme. Iran denies the charge and says it needs nuclear technology to meet electricity demand.
Washington has led international efforts to penalise Iran for failing to allay suspicions over its nuclear work.