Prime Minister Gordon Brown announced Tuesday that he was slashing the remaining British contingent in Iraq by nearly 20 percent. A beleaguered Iraqi leader said his own forces would be ready to take up the slack in the country's oil-rich southernmost province in two months.

Brown's one-day, unannounced swing through Iraq comes as U.S. military officials are concerned that the reduced British presence in the south could open security gaps along key supply and transit routes to Kuwait.

The roadways are a vital lifeline for U.S. forces. And everything that the Americans can't fly out of the country when they eventually leave must make the long and potentially dangerous road journey to Kuwait through Basra province.

Brown is said to be contemplating early elections in Britain, where the war is deeply unpopular. He arrived in Baghdad midmorning and went straight into a meeting with his Iraqi counterpart, Nouri al-Maliki.

"We are prepared to take over security of Basra within two months and we will," al-Maliki said after the meeting in his Green Zone office. "Basra will be one of the provinces where Iraqi forces will completely take over security."

Brown confirmed al-Maliki's plans and said, "as we move to overwatch, we can move down to 4,500" troops from the current level of 5,500. He promised to bring the 1,000 troops home by Christmas.

Last month, British troops vacated their last remaining base in downtown Basra, Iraq's second-largest city, 340 miles southeast of Baghdad. The British force now is based mainly at an air base on the fringes of Basra city inside Basra province.

The British leader said any further decision on troop withdrawals would be made next year. His visit overshadowed the opposition Conservative Party conference in Blackpool, England.

Brown spoke at the Green Zone residence of Britain's top commander in Iraq, Gen. Bill Rollo.

Later, he traveled to Basra, where he gave a five-minute speech in Basra to British, Australian and U.S. forces, commending their courage.

"What you are doing is making a big difference," he said. "You are building a democracy in this country by sustaining the people who want the people of this country and not terrorists to control the future of this country."

U.S. commander Gen. David Petraeus, who met briefly with Brown, gave qualified assent to the British leader's plan.

"I think that's actually quite doable. Basra currently has four battle groups, Iraqis are largely in the lead. There are innumerable challenges in the security situation in Basra ... but there are really Iraqi solutions that are emerging to some of these," the American commander said.

Britain's defense ministry said rocket and mortar attacks on their base at Basra airport had fallen sharply in the month since British troops left the city.

Nevertheless, Karim al-Miahi, the head of the Basra security committee and a member in the provincial council said, the departure of the British force from the city "had a negative effect on security in the city."

"Iraqi forces still are not able to control the situation which has deteriorated over the past three weeks. There has been an increase in assassinations of police and religious leaders. As for the areas around the British base, the situation is more stable. Shelling there has stopped," he told The Associated Press.

Abdul-Maunim Karim, 50, a retired sailor who lives near the newly vacated presidential palace, agreed the area was quieter because the shelling had stopped. "But throughout the city violence remains at about the levels before the British troops left."

Former Prime Minister Tony Blair was greeted with a salvo of mortars as he made a final visit to the camp before leaving office in June. Soldiers at the time were reporting as many as 10 strikes a day.

British military leaders hope their troops will remain in charge only of training Iraq troops and border guards, securing key supply lines and responding to emergencies when called on by Iraqi commanders.

The announcement about the planned troop reduction in Basra came as the country saw record low casualty numbers for September, suggesting U.S.-led forces are making headway against extremist factions and disrupting their ability to strike back.

The U.S. military toll for September was 65, the lowest since July 2006, according to figures compiled by AP from death announcements by the American command and Pentagon.

Also Tuesday, at least 13 people were killed, including two women, a child and four police officers, in five separate attacks. A physician was shot to death as he drove his car in Iskandariyah south of the capital.