Updated

Iranian officials say the country is considering a harder line in nuclear talks with world powers, threatening to step up uranium enrichment unless the West makes immediate concessions on sanctions.

The proposed demands have not yet been adopted as a negotiating policy, but they suggest economic pressures have pushed Iran to consider ultimatum-style tactics to seek relief from sanctions.

Mansour Haghighatpour, deputy head of the parliament's influential National Security Committee says failure to negotiate a deal could clear the way for Iran to enrich uranium above the current highest level, 20 percent.

The West fears Iran's enrichment program could lead to nuclear weapons. Iran says its nuclear program is for peaceful purposes.

Several rounds of talks have produced little progress. No date has been set for their resumption.