An agreement in which Libya would accept responsibility for the bombing of Pan Am Flight 103 could be reached within weeks, relatives of victims said after meeting with a top US State Department official.But family members of the 270 people killed in 1998 when Pan Am 103 exploded over the Scottish town of Lockerbie said they were neither shown a draft Libyan statement they believe was under consideration nor promised a deal would be cemented.A source close to talks between Libya, the United States and Britain said on Tuesday that Tripoli had agreed to accept responsibility for the bombing and compensate the victims’ families. But US officials also said it may be weeks, if ever,before a final agreement is signed, sealed and announced.‘‘The overwhelming feeling, was, yes, there is some sort of a statement which has been, if not agreed to, at least is certainly being passed around and this whole thing may be settled within a matter of weeks,’’ said Dan Cohen, whose daughter Theodora, then 20, was killed in the bombing.He said lawyers for the families would fly to Paris next week to set up escrow arrangements for payments that may reach $10 million per victim, or some $2.7 billion in total.‘‘I think there absolutely is progress,’’ Rosemary Wolfe, whose stepdaughter Miriam died, told reporters after meeting US Assistant Secretary of State William Burns.‘‘It will take a little while. I think probably days and weeks’’ before the evaluation is completed and any deal might be final, said a senior US official, who asked not to be named. Pan Am 103 exploded in December 1988, killing 259 mostly American passengers and crew, and 11 people on the ground. Reuters