NEW DELHI (AFP) -- India will engage in delicate diplomacy this week during talks with Washington on a crucial civilian nuclear deal and with nuclear Iran over energy and regional issues, analysts said.

"India will have to maintain a very fine balance," said C.U. Bhaskar, an analyst with the Institute of Defense Studies and Analyses, to avoid raising the ire of, and damaging its economic ties with, both nations.

Energy cooperation will be high on Indian Foreign Minister Pranab Mukherjee's agenda when he visits Tehran, his first official trip outside South Asia since taking office in May.

His talks today and tomorrow come amid growing U.S. pressure on countries for tougher sanctions against Iran for its nuclear program.

India and Iran are expected to discuss two multi-billion dollar gas deals including a pipeline that would cross Pakistan to help meet demand in energy-hungry India.

Mukherjee is also almost "certain to discuss the situation in the region," an Indian official said, as tension mounts over Tehran's nuclear program and the U.S. military buildup in the Persian Gulf and Iraq.

In Washington, India's special envoy on the U.S. nuclear deal, Shyam Saran, is expected to conclude a deal that lifts three decades of U.S. sanctions barring the transfer of civilian nuclear technology and equipment to India.

The U.S. Congress in December gave the go-ahead to Washington to begin the negotiations with New Delhi, seen as the high watermark of the rapidly warming ties between the two nations.

But the ties did not stop U.S. Ambassador to New Delhi, David C. Mulford, last week warning that Washington would be following Mukherjee's Iran visit.

Mulford also told reporters Washington "discouraged" any commercial dealings with Iran. The U.S. has placed economic sanctions on Tehran that include halting cooperation with governments and companies abroad that invest in Iran.

Bharat Karnad, of the New Delhi-based Centre for Policy Studies, said New Delhi had to watch its step carefully or endanger the growing U.S. relationship.

It "is a cross that India has to bear as, to an extent, the successful conclusion of the India-U.S. accord depends on satisfying the U.S. on certain issues," the analyst said. Analyst Bhaskar and India's former envoy to the UN Conference on Disarmament, Arundhati Ghosh, agreed Mukherjee's visit to Iran was "very important" and the talks with the United States were "delicate."

"In diplomacy, there are always grey areas. The foreign minister's visit is key as it is important not to make Iran feel isolated at this point," Bhaskar said. "India could play a valuable role as facilitator depending on the situation," he added.

Indian officials, however, dismissed suggestions New Delhi has a "high-wire balancing act" on its hands. "Not at all," said a senior official who describes New Delhi's engagements with "strategic partner" Tehran on energy and other issues as pursuing the "national interest."

"India, as the Prime Minister (Manmohan Singh) has stated in Parliament and at other times, follows an independent foreign policy. There is no question of any pressure from any quarter. But New Delhi is not in favor of another nuclear weapon state in the region," the official said. He added "India is also against the use of force to make Iran stop its nuclear program."