US Secretary of State Condoleezza Rice has arrived in India on the initial leg of her first major tour of Asia.
Condoleezza Rice will visit six nations in a week-long tour of Asia
Ms Rice will meet Indian Prime Minister Manmohan Singh on Wednesday, with the focus expected to be on the improving relations between India and Pakistan.
Her week-long tour will then take her to Islamabad, Afghanistan, Japan, South Korea and finally China.
China's relations with Taiwan and US efforts to limit North Korea's nuclear ambitions may dominate the trip.
Ms Rice's talks with India's prime minister and Foreign Minister Natwar Singh may also look at developments in Kashmir and the political situation in Nepal.
She will leave New Delhi on Wednesday evening bound for Islamabad, where Pakistan's role in the US war against terror may be on the agenda.
Talks in India may focus on the improving relations with Pakistan
The BBC's Jonathan Beale, travelling with the tour, says much of Ms Rice's energy will be devoted to US attempts to persuade North Korea to give up its nuclear weapons.
Speaking during her flight to India, Ms Rice repeated Washington denials that it planned to attack North Korea and stressed the importance of sticking with stalled six-party talks on Pyongyang's nuclear weapons.
"The six-party framework is the best and most reliable way to deal with the North Korean programme, because it has all of the important neighbours at the table," she told reporters.
North Korea pulled out of the talks - which also involve South Korea and Japan - last month.
Meanwhile, a North Korean foreign ministry spokesman warned his country would take measures "including bolstering its nuclear arsenal" to prevent an attack by the US and "keep the equilibrium of forces in the region".
Ms Rice's trip will also focus on China's increasingly tense relationship with Taiwan, our correspondent says.
Washington on Monday described a new Chinese law giving Beijing the legal right to use force against Taiwan if it moves towards independence as "unfortunate".
Ms Rice said rising military spending by China was a concern because of the growing tension between it and Taiwan but stressed that the US was no threat to China.
While in Seoul, Ms Rice is expected to discuss the future of the large US troop deployment in South Korea.