Ammon News - In recent weeks, Iran has dramatically escalated efforts to seal off its cache of near bomb-grade uranium, deliberately collapsing tunnels and booby-trapping entrances with explosive mines, according to five sources familiar with US intelligence.

Getting to the roughly half-a-ton of highly-enriched uranium is now far more difficult, dangerous and time-consuming than it already was just a month ago, when President Donald Trump was publicly signaling that he might order the US military to seize it, the sources said.

The new fortifications by the Iranians add an additional layer of complexity to the Trump administration’s proposed deal with Tehran to remove and destroy its uranium, and the move raises questions about who will take on the dangerous task of digging it out.

Iran’s diplomatic delegation to the United Nations did not immediately return a request for comment, and the White House did not immediately reply to questions from CNN.

Trump has repeatedly stated that securing the material is a priority for the US in the ongoing negotiations to end the war and re-open the Strait of Hormuz, which Iran has effectively closed.

And according to a senior administration official who briefed reporters Friday, the two sides are inching closer to a deal that would require Iran to turn its enriched uranium over to the US. It would be destroyed on site and then taken out of the country, according to that official.

But US and Iranian officials have offered conflicting accounts of the tentative deal, and its precise terms remain unclear. The purported text of a draft deal leaked to a semi-official Iranian news agency Friday, triggering an angry outburst from Trump on social media.