Oil prices climbed early Thursday as markets zeroed in on the prospect of US action against Iran, lifting energy shares alongside crude - with West Texas Intermediate above $66 a barrel. The US military build-up in the Middle East means Iran's window to reach a diplomatic agreement over its atomic activities - which Tehran insists is for peaceful domestic energy purposes - is at risk of closing fast, according to the head of the United Nations nuclear watchdog speaking to Bloomberg Television. 

At this moment the Trump-assembled armada threatening Iran includes two aircraft carriers, a dozen warships, hundreds of jets, and advanced air defenses. Over 150 US military cargo flights have delivered weapons to the Middle East this month, with a surge of aircraft still headed to the region. Some say the build-up is already nearing Iraq war levels.

Director General Rafael Mariano Grossi underscored the clock is ticking. "There is not much time but we are working on something concrete," said Grossi, in reference to meetings in Geneva with Iranian diplomats. "There are a couple of solutions the IAEA has proposed.

IAEA inspectors haven't verified the state of Iran's stockpile of near-bomb-grade uranium or assessed the scope of damage dealt to enrichment facilities for more than eight months.

Ironically enough, it was the unprovoked surprise Israeli and US attacks which shut the door on such inspections, also after the White House itself insisted on several occasions that the Islamic Republic's nuclear program was "obliterated" in the series of US bunker-buster bomb attacks on Fordow, Natanz, and Isfahan. Which is it?

Bloomberg and various analysts have speculated that before the Israeli attacks in June, Iran had enough highly-enriched material to quickly craft about a dozen warheads, assuming the scenario Tehran issued the order to weaponize its nuclear program.

Grossi said he also met with Trump’s envoys on Tuesday in Geneva, alongside the IAEA's some six hours of meetings with Iranian diplomats. He asserted that an IAEA return to the damaged facilities in Fordow, Isfahan and Natanz "hinges on the possibility of a wider type of agreement."

"We are conscious of the fact that there is this political negotiation," Grossi added. However, the Iranians are likely going to remain deeply distrustful of the UN watchdog and Grossi himself, given that the surprise June attack resulted in Iranian officials accusing the IAEA team of leaking sensitive data on Iranian facilities to Israel.

This is perhaps why Grossi himself appears pessimistic when commenting on the potential the forge a new deal before US military action ensues.  "There cannot be a deal if the IAEA isn’t able to verify," said Grossi, who described to Bloomberg he's seeking a solution by threading the red lines set by both sides.

"It’s not impossible," he said. "There are certain things that Iran understands cannot be pursued. We have to provide the watertight verification there is no deviation."

Some reports say a US attack on Iran could come as early as this weekend...

As the second US carrier, the USS Gerald R. Ford, is about to enter the Mediterranean while headed toward the CENTCOM area of responsibility, regional analyst Levent Kemal observes, "The US military buildup in the Middle East is going beyond dialogue or gunboat diplomacy. This is clearly an important preparation for a war aimed at removing the Iranian regime from the regional power balance equation."