NEW DELHI (AFP) - Russian Foreign Minister Sergei Lavrov insisted on Sunday that marathon negotiations in Geneva to try to curb Iran's nuclear programme were "very substantial", despite failure to clinch an agreement.

Mr Lavrov backed the talks that ended early on Sunday, saying reducing the risk of nuclear proliferation "can only be done through negotiations".

"It is fundamentally important for us and the international community is very interested to eliminate the risk of nuclear proliferation, but this can only be done through negotiations," the minister said at a press conference in New Delhi, when asked about the Geneva talks.

"The strategy is to renounce threats and sanctions and proceed in a business-like manner. The new Iranian government has been very decisive in this area and the meeting was very substantial," Mr Lavrov, who attended the negotiations in Geneva, said.

The minister made the comments after meeting with his Chinese and Indian counterparts in New Delhi over regional security and economic issues. The meeting included security in Afghanistan, but was not thought to have included Iran.

Iran and world powers failed to clinch a deal on Sunday on Teheran's nuclear programme despite the lengthy talks in Geneva, dashing hopes of an agreement in the decade-old standoff.

But diplomats said significant progress had been made in the three days of negotiations, and that talks would resume on Nov 20.