British Prime Minister David Cameron on Thursday said Pakistan should rein in terror outfits, as the existence of terror groups in Pakistan was not acceptable.

Speaking during the joint press meet held in the national capital, Cameron said: "There is proof of existence of terror groups in Pakistan. We need to talk frankly with Pakistan on terror. (We) will help India to fight terror groups. Pak soil must not be used for terror."

Prime Minister Dr Manmohan Singh, on this occasion, said: "Pakistani soil must not be used against terror. Pakistan needs to do more to fight terror."

"Pakistan Foreign Minister Shah Mehmood Qureshi should have avoided press meet remarks. We will restore dialogue sooner or later with Pakistan," he added.

Earlier today, notwithstanding angry reactions from Islamabad, Cameron refused to retract his remarks that Pakistan must stop the "export of terror", insisting that presence of terrorist outfits in that country was unacceptable.

Despite anger in Islamabad about his remarks about Pakistan's record on terrorism, Cameron said: "I don't think the British taxpayer wants me to go around the world saying what people want to hear."

He denied that the row had overshadowed his trip to India and maintained that he had good relations with Pakistan, whose president will be visiting him at his country retreat at Chequers next week.

Cameron said he was not responsible for the headlines generated by his comments, but said: "I think what is absolutely clear is, it's not acceptable for, within Pakistan, there to be terrorist groups threatening Pakistan itself but also other countries, including British people, whether in Afghanistan or back at home."

Asked whether he regretted damaging relations with Pakistan, he said: "I don't accept that they have been damaged. We have very good relations with Pakistan - I have a meeting with President (Asif Ali) Zardari next week in the UK and I look forward to discussing these and other issues." (ANI)