Since it agreed in 2003 to pay compensation for the Lockerbie bombing, Libya has been pushing to get back into the international fold, and Britain has made moves to help.
But disapproval at the speed of Libya's rehabilitation has been expressed by the relatives of some of the 270 people who died when Pan Am Flight 103 was blown out of the skies over the small Scottish town 15 years ago.
Washington has now announced that until it sees tangible action from Colonel Muammar Gadaffi's regime, United States sanctions that deny Libya access to hundreds of millions of dollars in property and bank assets will not be lifted.
Colonel Gaddafi is coming out of international isolation
The era of treating Libya as a dangerous pariah may be all but over but few in Washington have forgotten the events of nearly two decades ago that led President Ronald Reagan to publicly dub the Libyan leader the "mad dog of the Middle East".
The US trade embargo was imposed in 1986 after a period of tension between Libya and the US that culminated in American air strikes against major targets in the capital, Tripoli, and elsewhere.
President Reagan claimed then that there were strong reasons to suspect Libya of being involved in international terrorism. And this was before the Lockerbie bombing of December 1988.
Some relatives of the Lockerbie bomb are urging caution
Under the embargo, all American trade with Libya is controlled by the US treasury and Libyan assets in the US are frozen.
In 1991 the United Nations imposed its own sanctions after Washington accused Libya of planning the Lockerbie attack. These sanctions were lifted last year after Tripoli agreed to pay compensation to the families of the Lockerbie victims.
But despite this, and Libya's recent decision to drop its pursuit of weapons of mass destruction, the US sanctions remain in place. And even the income generated by Libya's oil reserves have not compensated for the huge cost they impose on the North African state.