India's Narendra Modi arrived in Pakistan on Friday, his first visit as prime minister to this Islamic nation that has been India's long-standing archrival in the region.
The previously unplanned visit is a sign of improving relations between the two nuclear-armed neighbors. The two heads of government also had an unscheduled meeting at the Paris climate change talks earlier this month.
Since independence from Britain in 1947, India and Pakistan have fought three wars, two of them over Kashmir, the Himalayan region that both claim in its entirety.
Modi landed on Friday afternoon in the eastern city of Lahore and met with Pakistani counterpart Nawaz Sharif, state-run media reported. State-run Pakistani TV showed Modi being received by Sharif.
Security forces and troops were beefed up at the Lahore International Airport shortly before Modi's arrival. Earlier in the day, Pakistani Foreign Ministry spokesman Qazi Khalilullah said India had informed Pakistan about the visit on Friday. He refused to share any details.
From a stop earlier Friday in the Afghan capital of Kabul, Modi tweeted that he is "looking forward to meeting" Sharif in Lahore, "where I will drop by on my way back to Delhi." He said he also called Sharif and wished him happy birthday.
Analysts said the visit was an important development.
"I think it is going to play a significant role in improving ties between the two South Asian archrivals," said Amanullah Memon, a professor of international relations at a private university in the capital, Islamabad.
After a year of rising tensions, top security officials from India and Pakistan held talks in Thailand's capital earlier in December, discussing a range of issues, including the disputed Kashmir and ways to maintain peace along the countries' shared border.
Also, two weeks ago, Indian External Affairs Minister Sushma Swaraj visited Pakistan to attend a meeting on Afghanistan. After her talks with Pakistan, she said both sides agreed to resume talks on several topics.
India accuses Pakistan of arming and training insurgents fighting for Kashmir's independence from India or its merger with Pakistan, a charge Islamabad denies. More than 68,000 people have been killed in the violence, which began in 1989.
India also wants Pakistan to bring to justice Hafiz Muhammad Saeed, the alleged mastermind of the 2008 Mumbai terror attacks that killed 168 people. Saeed lives in the open in Pakistan and often appears in TV interviews.
Another concern for both countries is the frequent skirmishes along their border in Kashmir. A cease-fire along the India-Pakistan line of control that serves as the Kashmir boundary has largely held since 2003, but firing and gunbattles are fairly common, with each side routinely blaming the other.
Associated Press Writer Ashok Sharma contributed to this reports from New Delhi, India.