LONDON — British Prime Minister Tony Blair rejected suggestions that the ongoing violence in Iraq was because of flawed planning by the US-led coalition, but said he felt a deep responsibility to end the killings.Blair said yesterday that Washington had not put pressure on London to maintain its troop numbers in Iraq, despite US President George W. Bush’s plans to send in an additional 21,500 troops.

Britain hopes to cut its 7,000-member force in the southern city of Basra by several thousand by midyear.

“We have absolute responsibility to put things right. What I completely dispute is that the reason Iraq has got the difficulties it has ... is simply because of issues to do with planning before the war,” Blair said in an interview on British Broadcasting Corp. television.

Blair said British forces had completed an operation to hand front-line security responsibility to Iraqis in Basra, where he said the security situation is different from what US troops face in Baghdad.

The transfer of front-line security is a significant step toward handing Iraqi authorities total control of Basra province.

“The operation that we have been conducting in Basra is now complete and that operation has specifically been to put the Iraqi forces in the main front-line control of security in the city,” Blair said.

“And it has been successful as an operation and as a result there has been reconstruction that has come in behind it and we have been able to make real progress,” he said.

Blair, who has said he will step down as prime minister by September after a decade in power, has seen his foreign-policy record overshadowed by his role as Bush’s leading ally in the unpopular war. In yesterday’s interview, he disputed suggestions he should bear responsibility for deaths in Iraq.

“They are being killed by people who are deliberately using terrorism to try to stop the country getting on its feet,” Blair said.

“It’s not a question of being culpable. I feel a deep sense of responsibility for putting the situation right.”