British forces formally handed over responsibility Sunday for the last region in Iraq under their control, marking the start of what Britain hopes will be a transition to a mission aimed at aiding the economy and providing jobs in an oil-rich region beset by militia infighting. With the handover of Basra, in Iraq's far south, nine of the country's 18 provinces have reverted to Iraqi government control. The commander of British forces in Basra, Maj. Gen. Graham Binns, said the city had been pulled from the grip of its enemies. "I now formally hand it back to its friends," Binns said shortly before he added his signature to papers relinquishing responsibility for the overwhelmingly Shiite region home to most of Iraq's oil reserves. "We will continue to help train Basra security forces. But we are guests in your country, and we will act accordingly." Mowafaq al-Rubaie, Iraq's national security adviser, said his government was ready and called on Basra's citizens to work together. "Your unity is essential in rebuilding your city. You have to come together and unify Sunnis, Shiites, Muslims and non-Muslims and nationalists," he said. US officials worry that a power vacuum could heighten the influence of Iran and threaten land routes used by the Americans to bring ammunition, food and other supplies from Kuwait to troops to the north. US President George W. Bush predicted in January that Iraq would assume control all of its provinces by November, but the target date has slipped repeatedly, highlighting the difficulties in developing Iraqi police forces and the slow pace of economic and political progress. American forces retain control of seven of Iraq's provinces, including Baghdad and some of the country's most volatile areas, such as Diyala and Anbar. Binns said British forces would remain to help the Iraqis. "Our help will continue to be one of assistance, not interference. To support, not to direct. To listen, not to ignore," Binns said. "This will be achieved by actions, not just by words. This is our promise to you, the people of Basra." British Foreign Secretary David Miliband, who also attended the handover ceremony, said Britain would remain a "committed friend," of Iraq. "Our aim is to see an Iraq run by Iraqis for all Iraqis," he said. In Baghdad, there was some skepticism that Iraqi forces were ready to take control in Basra, but many agreed that the handover was a positive sign. "I hope it will be followed by similar steps across the country. Such steps are good for Iraqis," said Awatif Qazaz, a Baghdadi woman. But Osama Juwad said he feared the security forces were infiltrated by militias. British officials have said they will retain the ability to help Iraqi troops quickly if widespread violence erupts, but they are also reducing the number of troops in the country from 4,500 to 2,000 by spring. In the months soon after Saddam Hussein was toppled, there were about 40,000 British troops in Iraq. Britain's participation in the US-led invasion of Iraq and the ongoing presence of troops is deeply unpopular in Britain - as is the US$12 billion annual cost of operations there. A total of 174 British personnel have died in Iraq since the March 2003 invasion.