(Corrects information about advanced centrifuges in sixth paragraph.)

In the prelude to talks that begin tomorrow in Kazakhstan, Iran has gone out of its way to damp expectations that it can be persuaded to slow its nuclear program.

Days before sitting down with China, France, Germany, Russia, the U.K. and the U.S., Iran made two announcements: that it had discovered new deposits of raw uranium and had identified locations for 16 nuclear power stations to add to the one it operates in Busheir.

Apart from signaling an intention to power forward, neither pronouncement meant much. Uranium is a fairly common metal; deposits are significant only if they are high-quality and economically recoverable. As for nuclear power plants, Iran can draw up plans, but no one is going to sell it another station, and it doesn't have the technology to build its own.

At the same time, Iran has continued to upgrade the nuclear facilities it does have in ways that complicate reaching an agreement. According to a Feb. 21 International Atomic Energy Agency report, Iran is using one of its putatively legitimate nuclear sites, the Tehran Research Reactor, to help develop what may be a weapons-related facility, a heavy-water reactor under construction at Arak. In November, the Tehran Research Reactor began testing a fuel assembly designed to power the Arak plant.

This development undercuts the previously discussed possibility of Western countries providing the Tehran reactor with fuel in exchange for Iran halting production of 20 percent enriched uranium and sending part of its stocks outside the country.

What's more, the Iranians are rapidly building their enrichment capacities. IAEA inspectors found that Iran has boosted the rate of installation of first-generation centrifuges at the Fuel Enrichment Plant at Natanz by 55 percent, from about 450 per month to 700 per month. And it has begun to install advanced centrifuges that are four to five times more productive.

If Iran increased its stockpile of 20 percent enriched uranium to 250 kilograms (it is known to have 167 kilograms, or 368 pounds), it would need about a month to produce the 90 percent enriched material necessary for a weapon, using its current capabilities. The installation of additional and advanced centrifuges narrows that period and with it the time span the U.S. and allies would have to stop an Iranian bomb.

(Lisa Beyer is a member of the Bloomberg View editorial board.)