U.S. Secretary of State John Kerry on Sunday urged fast-growing India to work with the United States on global warming before it's too late. "The irreversible climate challenge is speeding towards us, crying out for a global solution, `' he said.

Kerry spoke on climate change in a speech in New Delhi, the second stop on his two-week swing through the Mideast and Asia, just two days before President Barack Obama is to unveil his long-awaited plan for the United States on the issue.

"The world's largest democracy and its oldest one must do more together, uniting not as a threat to anyone, not as a counterweight to a region or some other countries, but as partners building a strong, smart future in a critical age," Kerry said in a reference to how India is often viewed as a counterbalance to China.

People consulting with White House officials on Obama's plan say they expect the president to put forth regulations on heat-trapping gases emitted by coal-fired power plants that are already running. Environmental groups have been pleading with Obama to take that step, but the administration has said it's focused first on controls on new power plants.

More than half of India's power comes from coal and while the U.S. has emission issues of its own, it wants to see India and other nations in the region rely less on old, coal generation facilities. The U.S. is backing a Turkmenistan-Afghanistan-Pakistan-India pipeline that would bring energy to a power-starved region.

Speaking at a convention center to a crowd of several hundred businessmen, students and others, Kerry noted that federal scientists in May reported that the concentration of carbon dioxide in the atmosphere passed 400 parts per million _ a level never before experienced by man.

"When the desert is creeping into East Africa, and ever more scarce resources push farmers and herders into deadly conflict ... then this is a matter of shared security for all of us. ... When the Himalayan glaciers are receding, threatening the very supply of water to almost a billion people, we all need to do better," he said.

During his first trip to India as secretary of state, the top U.S. diplomat was expected to discuss a myriad of other topics, including enhancing security in the region and prospects for finding a political resolution to the war in Afghanistan.

As NATO troops leave, India fears the country could fall into the hands of a Taliban-led regime, endangering many of India's interests there. Kerry reassured India, which has invested more than $2 billion to reconstruct Afghanistan, that the U.S. commitment to the Afghan people will not end at the close of next year when NATO-led combat troops complete their withdrawal.

In meetings before Kerry heads to Saudi Arabia on Tuesday, the U.S. expects Indian officials will want to query Kerry about prospects for peace talks with the Taliban. U.S. talks were scheduled to begin in coming days, but a last-minute diplomatic rift over how the Taliban rolled out their new political office in Doha, Qatar, has threatened to scuttle the talks.

"Obviously, we are very realistic about the difficulties of making progress. Making peace is never easy, and a final settlement may be long in coming," he said.

"And let me be clear: Any political settlement must result in the Taliban breaking ties with al-Qaida, renouncing violence and accepting the Afghan constitution, including its protections for all Afghans, women and men. Afghanistan cannot again become a safe haven for international terrorism."

Kerry also spoke about India's archrival, Pakistan.

There is widespread hope that Pakistan's new President Nawaz Sharif will try to improve relations with its Indian neighbor, thus reducing the chance of a fourth major war between the nuclear-armed foes.

But India has been frustrated by Pakistan's failure to crack down on Islamic extremists, which have strong historical links with Pakistani intelligence. Kerry called on Pakistan to continue normalizing trade relations with Pakistan. "Just last year, bilateral trade increased 21 percent," he said.

Washington wants New Delhi to speed up economic reform to increase U.S. business and trade opportunities with India. In the past decade, bilateral trade has increased five-fold, but Kerry is expected to share the concerns of the U.S. business community about trade and about other problems American businessmen are facing in India.

More than 150 U.S. lawmakers teamed up with American business groups last week to press the Obama administration to further press India to ease policies they claim are bad for American exports, jobs and innovation.