Iran has significantly stepped up the pace at which it is enriching uranium, shortening the time it would take for it to reach a nuclear threshold, two Israeli newspapers reported on Monday.

"Iran has broken new records in terms of the pace at which it has been enriching uranium, and it has continued to race ahead so as to create as short a 'storming distance' as possible between it and the bomb," the Maariv daily said.

Sourcing the story to unspecified "intelligence reports," the paper said Iran had been able to up the pace of enrichment due to the fact that it was now operating "close to 10,000 centrifuges" including "a new type of centrifuge that is far more sophisticated."

Israel says a nuclear Iran would pose an existential threat to the Jewish state and officials believe Tehran may be on the cusp of "break out" capacity -- the moment when it could quickly produce weapons-grade uranium.

A similar report on the Ynet news website, the online version of the Yediot Aharonot newspaper, had identical figures but did not cite a source.

"The data indicate that Iran has significantly increased the pace of its uranium enrichment over the past four months," it said, without giving details.

"Currently the Islamic republic produces 230 kg (507 pounds) of LEU (low-enriched uranium) each month and 12 kg (about 26 pounds) of uranium enriched to a fissile concentration of 20 percent," it said.

It said Tehran currently held stocks of some 160 kg (352 pounds) of 20 percent enriched uranium, which was about 100 kg, or 220 pounds, less than the amount required to produce a bomb.

"Should the Iranians continue to enrich uranium at the current pace, they will have some 260 kg (about 570 pounds) of uranium refined to a fissile concentration of 20 percent in January or February of 2013," the website said.

"With this amount, it would take Iran only about two months to produce weapons-grade uranium for a nuclear warhead or bomb -- a 'nuclear threshold' situation."

In May, the IAEA nuclear watchdog published figures showing Iran had already produced 146 kilos of 20 percent-enriched uranium since February, of which just under a third had been converted into fuel plates for the Tehran research reactor, rendering it unsuitable for further enrichment.

Israel, which is widely believed to have the Middle East's only, albeit undeclared, nuclear arsenal, has warned that a military option cannot be ruled out to prevent Iran from developing an atomic weapons capability. Tehran insists its nuclear programme is for peaceful purposes only.