The world's two most populous nations will try to remove a long-term irritant in their relations by signing a border agreement.

The Border Defense Cooperation Agreement may be signed during Indian Prime Minister Manmohan Singh's visit to China, which starts on Tuesday, Press Trust of India said.

Manmohan Singh, Indian Prime Minister.

The deal, along with Singh's visit, is a sign of improved Sino-Indian ties, experts said. Premier Li Keqiang visited India in May.

In a statement before departing on his five-day trip to Russia and China on Sunday, Singh indicated that the proposed border cooperation agreement with China will top his agenda.

"India and China have historical issues, and there are areas of concern. The two governments are addressing them with sincerity and maturity, without letting them affect the overall atmosphere of friendship and cooperation," Singh said.

"I will be discussing some of these issues as part of strategic communication between leaders with a forward-looking and problem-solving approach."

Singh said India and China have reached an important consensus on maintaining peace and tranquility on the border and have made preliminary progress toward the settlement of boundary issues.

Hu Shisheng, director of the Institute of South and Southeast Asian and Oceanian Studies at the China Institutes of Contemporary International Relations, said the defense deal will be "very important in controlling border crises".

"The two nations have established some mechanisms for managing border issues. Now if they can have this legally binding agreement there will be a double guarantee."

"Singh has forged the political basis for the two Asian giants to explore deeper cooperation," Hu said.

Singh said, "In my last nine years in office as prime minister, I have worked closely with Chinese leaders to establish a strategic and cooperative partnership and put in place comprehensive mechanisms for cooperation and dialogue and to address bilateral issues between our two countries."

On Wednesday, after a discussion and lunch with Li, Singh will dine with President Xi Jinping, Press Trust of India said. He will also give a speech at the Party School of the Central Committee of the Communist Party of China.

Ye Hailin, an expert on Asia-Pacific Studies at the Chinese Academy of Social Sciences, said there has been speculation that Singh might raise the idea of building an industrial base in India especially for Chinese enterprises.

"That will be a great way to help balance trade between the two and reshape the economic structure of India," Ye said.

The two nations aim to boost trade to $100 billion in 2015, from $66.5 billion last year.

Qu Xing, president of the China Institute of International Studies, said Li mentioned building an economic passage linking East Asia and South Asia in his May visit to India. "This time it is expected that the two sides can discuss details of the plan."

Singh said on Sunday that the nations are "exploring new ways, like sub-regional connectivity, to impart dynamism to our cooperation."

In addition to Singh, the prime ministers of Russia and Mongolia are also visiting Beijing this week.

Contact the writers at lixiaokun@chinadaily.com.cn and zhangyunbi@chinadaily.com.cn