Russian missiles supplied to rebels in eastern Ukraine could be used to bring down more civil airliners, Foreign Secretary Philip Hammond has warned.
Mr Hammond called on President Vladimir Putin to cut off the supply of weapons to the separatist groups who have been blamed by the West for the downing of Malaysia Airlines flight MH17 with the loss of 298 lives - including 10 Britons - on July 17.
Following the decision of the EU and US to impose the toughest sanctions on Russia since the end of the Cold War, Mr Hammond said that the West's confidence that Moscow was moving towards becoming part of the international community had been "shattered" by its actions in Ukraine and that it was now "certainly not an ally."
He was speaking as international Investigators continued their search for the remains of around 80 victims of MH17 spread over an area of eight square miles around the village of Hrabove, in a process expected to take weeks.
The team of 70 Dutch and Australian investigators using sniffer dogs were able to reach the site for the second consecutive day and recovered more human remains and personal belongings.
Speaking to the Sunday Telegraph, Mr Hammond blamed Mr Putin for failing to ensure access to the crash site in the days after the tragedy.
"It is an unspeakable abomination that two weeks after this crash, there are still bodies on the crash site unrecovered and the Russians have not used their influence with the separatists," said the Foreign Secretary.
"I said last week that there is one man who can snap his fingers and make this happen and he hasn't done so. He must now do so."
He set out what Mr Putin must do to begin de-escalating the situation: "Cut off the supply of weapons to the separatists, in particular the supply of sophisticated weapons that could proliferate anywhere, could be used to down other civil airliners - and if they are, Russia will have to be held accountable for any such actions in the future - and stop destabilising and interfering in a sovereign nation."
Mr Hammond said it would take time to "rebuild trust" with Russia.
"We thought that Russia was becoming part of the community of nations, slowly but surely," he said. "And over the last year our confidence in that has been shattered."
Asked whether Russia was now an ally or an enemy, he replied: "It's neither at this stage. It is certainly not an ally. It is not an enemy but we have a relationship with Russia at the moment which I would describe as more adversarial than partnership."