US Secretary of State John Kerry arrived in Geneva Tuesday to meet his Iranian counterpart as global powers seek to accelerate talks to reach a deal on reining in Iran's nuclear programme.

Iranian Foreign Minister Mohammad Javad Zarif suggested Monday that a more active role for Russia could be one way to speed up the talks, with a new deadline looming on July 1 for a comprehensive agreement.

Kerry has said the aim of his talks with Zarif on Wednesday is to "take stock" and provide guidance for their negotiating teams ahead of fresh discussions by global powers known as the P5+1 due to resume here on Sunday.

The top US diplomat also told reporters on Monday during a stop in India that he hopes to "accelerate the process to make greater progress."

Diplomats fear that time may be running out, after two earlier deadlines for an accord were missed.

American lawmakers are eager to impose new sanctions on Iran as the Obama administration has sought to hold them off, warning it could scuttle all hopes of a deal.

Washington's UN envoy Samantha Power said Monday that ratcheting up sanctions against Iran would likely torpedo the negotiations.

"Imposing new sanctions will almost certainly end a negotiations process that has not only frozen the advance of Iran's nuclear program, but that could lead us to an understanding that would give us confidence in its exclusively peaceful nature," Power told a US think-tank.

"If we pull the trigger on new nuclear-related sanctions now, we will go from isolating Iran to isolating ourselves," she said.

Under an interim deal agreed in November 2013, Iran's stock of fissile material has been diluted from 20 percent enriched uranium to five percent, in exchange for limited sanctions relief.

This would push back the "breakout capacity" to make an atomic weapon, which Iran denies pursuing.

But after extending the deadline for a deal due to lingering gaps, negotiators are keen to seal a ground-breaking accord.

"A more active Russian role is an important element in accelerating the final settlement of questions for a global nuclear agreement," the Iranian minister Zarif was quoted as saying on state media.

Ryabkov, who heads up the Russian negotiating team under the P5+1 talks, said good ties between Tehran and Moscow can still help "a rapid settlement of nuclear relations relating to Iran."

Kerry has said that the United States hopes to see an outline accord in March, perhaps leaving some of the complex technical aspects to be hammered out by the teams ahead of the end of June.