Correction: An earlier version of this story misid`entified the president of Congo. The story has been updated to identify him correctly as Joseph Kabila.

India is preparing to withdraw its four remaining Mi-35 attack helicopters from the U.N. mission in Congo early next month, ending years of Indian air superiority in the war-racked nation and depriving the United Nations of its most vital military asset as the country heads into a landmark presidential election.

The Indian drawdown will deal a blow to the U.N. mission, known by its French abbreviation, ­MONUSCO, which has depended on Indian troops and aircraft to ensure it can protect civilians and conduct humanitarian operations in a sprawling central African nation the size of Western Europe.

But it also points to a growing reluctance by states to supply U.N. peacekeeping missions with costly combat aircraft and other advanced logistical and communications equipment needed to fulfill complex mandates in places such as Congo and Sudan.

As the United States and other Western powers have retreated from U.N. peacekeeping over the past decade, India and a handful of other developing and emerging powers have filled the gap, supplying the United Nations with the bulk of its more than 100,000 peacekeepers needed to run the world’s second-largest expeditionary force, after the U.S. military. India’s efforts have been particularly notable because of its capacity to deploy combat helicopters and other advanced military gear in Africa and the political will to use them.

This month, India rejected a request by the United Nations to extend the helicopter contract in Congo when it expires July 4. “India cannot be the only place in the world with attack helicopters,” Manjeev Singh Puri, India’s deputy ambassador, said in an interview. “We have capacity restraints.”

Indian officials say they need the helicopters to fight Maoist insurgents, who originated in West Bengal and are active in several areas.

Its decision to scale back its military commitment in Congo comes as France is preparing to introduce a Security Council resolution calling on the U.N. peacekeeping mission there to play a greater role in ensuring the protection of civilians in the months leading up to the November election. The absence of combat helicopters will limit the mission’s ability to carry out such responsibilities and might even force the United Nations to close some of its more remote outposts in eastern Congo, according to human rights activists and U.N. officials.

“I am obliged to note that [the United Nations’] military operations are being negatively impacted by the shortage of military helicopters,” Roger Meece, the U.N. special representative, warned the Security Council last week. “This problem will become worse absent new contributions.”

India’s international identity has long been shaped by its role in U.N. peacekeeping. More than 100,000 Indian troops have served in missions in the past 50 years. Today, India has more than 8,500 peacekeepers in the field, more than twice as many as the United Nations’ five big powers combined. In supporting India’s bid for a permanent seat on an enlarged Security Council last November, President Obama cited “India’s long history as a leading contributor to United Nations peacekeeping missions.”

For now, New Delhi remains committed to keeping more than 4,000 uniformed personnel in Congo through the election. But Indian officials have bridled at its continued lack of influence despite its contributions to the United Nations. Its bid for a permanent seat on the Security Council appears stalled, and traditional powers such as the United States, Britain and France continue to make all the important decisions on peacekeeping missions and get the most influential U.N. jobs.

The drawdown comes as a gathering of large troop contributors, including Bangladesh, Pakistan, Nigeria and Uruguay, have reached a deadlock with the world’s wealthiest donors over how much money they should pay to run the 15 peacekeeping operations. The budget standoff threatens to upend an informal arrangement that requires rich countries to pay most of the costs of peacekeeping, while poorer countries supply the troops. Uruguay, which withdrew one CASA-212 fixed-wing airplane from Haiti in April, has threatened to withdraw nearly 1,300 troops from Congo, according to Security Council diplomats and U.N. officials.

“There is a huge mismatch between the mandates the Security Council gives the peacekeeping missions and the resources they are willing to provide; the rich countries are the worst offenders,” said Anneke Van Woudenberg, the senior Congo researcher at Human Rights Watch. “Where are the Europeans? Where is the United States? Where are the Canadians?”

The story of India’s drawdown in Congo, documented in previously unpublished U.S. diplomatic cables obtained through WikiLeaks, underscored the heightened sensitivity of a newly ascendant power that has seen its reputation tarnished in Congo and that has said it is not accorded the respect it deserves on the world stage.

Indian troops in Congo have been accused of corruption, sexual misconduct, falling short in their obligation to protect civilians from violent militias and favoritism toward anti-government rebels, according to the U.S. cables.

India’s relationship with Congo hit a low point in 2008, when a tipsy Indian military colonel, at the end of his deployment in the country, was tape-recorded delivering a farewell toast to Laurent Nkunda, commander of a rebel force that had repeatedly trounced government troops but had been badly bloodied in confrontations with Indian peacekeepers. When the Security Council voted to increase the number of U.N. peacekeepers in November 2008, a period marked by an upsurge in violence around the eastern Congolese city of Goma, the Congolese government said it did not want any more Indian peacekeepers, according to the U.S. cables and an Indian official.

“Clearly elated over his return home (a state of mind undoubtedly made more intense by the many drinks he imbibed at the event) the colonel lauded Nkunda in his good-bye statement as a worthy opponent,” according to the U.S. cable.

Infuriated at the slight, India threatened to pull all of its troops, as well as 23 transport and attack helicopters, a move that would have crippled the mission. The rift played into the hands of Congolese hard-liners, who used the controversy to try to force the United Nations out of Congo. At one stage, government officials paid crowds to hurl stones at the Indian peacekeepers, according to a U.S. cable.

“It seems the [Government of India] has determined it has no desire to continue placing its troops in harm’s way in a country where they are not wanted,” said one U.S. cable. “A withdrawal of Indians troops and helicopter assets would be absolutely devastating to MONUC ability to carry out its mandate.”

In early 2009, the United States tried to coax the Congolese leadership to patch up relations with India, and to offer public expressions of appreciation for the role the Indians were playing in Congo. Finally, President Joseph Kabila wrote a letter to the Indian Prime Minister Manmohan Singh thanking India for its contribution to peace and asking it to stay.

New Delhi dropped its plans to withdraw the troops, but Indian diplomats put the United Nations on notice that it would gradually remove its helicopters. Several countries, including South Africa, Ukraine and Argentina, have expressed interest in providing replacement aircraft. But the U.N. has been unable to secure firm commitments, leaving the U.N. without its most powerful military asset.

Correspondent Rama Lakshmi in New Delhi contributed to this report.