India said Tuesday it would cut purchases of Iranian oil by 11 percent -- far less than many other countries -- following US pressure to isolate the Islamic republic over its disputed nuclear programme.

Indian refiners will import 15.5 million tonnes of crude from its Persian neighbour this fiscal year, a minister told parliament, down from 17.44 million tonnes last year.

The announcement came after US Secretary of State Hillary Clinton last week pressed India to lower its Iranian oil imports ahead of a US law taking effect next month to slap sanctions on nations buying oil from Tehran.

A spokesman for the US embassy in New Delhi said he could not comment on whether the cut would be sufficient for India to obtain a waiver from sanctions, already granted to Japan and the European Union.

"That decision will be made in Washington," Peter Vrooman told AFP.

The usually friendly ties between the United States and India have been tested by their differences over Iran, with which New Delhi has been openly looking to expand its trade links.

Junior oil minister R.P.N. Singh did not mention the increasing Western pressure in his speech to parliament, but said the move to reduce oil imports from Iran was part of a drive to diversify energy sources.

The Indian government is wary of being seen as bowing too easily to US demands. There remains a strong anti-Washington strain in Indian politics, a legacy of the countries' mistrust during the Cold War.

"India has been consciously trying to diversify its sources of crude oil imports to strengthen the country's energy security," Singh explained.

Washington has said the reduction in oil imports must be "substantial" to win a sanctions waiver, but it has not specified exactly how much each nation must cut.

The EU is poised to fully implement an embargo on Iranian oil from July 1, while Japan imported 36 percent less oil from Iran in March from a year earlier. South Korea also is promising big cuts.

China and India are Iran's biggest oil buyers and official Chinese figures showed its imports of Iranian oil fell by over half in March, even though Beijing, like New Delhi, has publicly resisted joining the Western sanctions drive.

Energy-scarce India, which imports four-fifths of its crude, says it shares the US anti-nuclear proliferation goals but it views Iran as an important source of oil to feed its economy's fast-growing needs.

India, which competes for influence with Pakistan in South Asia, regards Iran as an ally and vital partner in helping to stabilise neighbouring Afghanistan following the US planned troop exit.

The United States says Iran's nuclear drive is aimed at making an atomic bomb but Iran insists it is for civilian energy.

India's announcement came while the US Special Envoy and Coordinator for International Energy Affairs, Carlos Pascual, was in the country to further push New Delhi to reduce its imports in the wake of Clinton's visit.

With dollar payment routes drying up due to already imposed sanctions, India and Iran have clinched a deal under which New Delhi will pay for close to half of its Iranian oil purchases in rupees.

Iran will use the money to buy Indian goods. Large delegations from each country have already visited the other to explore trade opportunities.