Chinese President Xi Jinping arrived in India on Wednesday as the two Asian giants take steps to boost commercial ties. China has pledged to invest billions of dollars in Indian railways, industrial parks and roads, but ties between the nuclear-armed nations have long been held back by distrust, mostly over their contested border.

Here are some facts about India-China relations and issues likely to come up for discussion:

BORDER DISPUTE – China beat India in a brief border war in 1962 and relations have remained sour over their still-disputed 3,500-km (2,200-mile) frontier. India has reported a rise in incursions by Chinese troops in recent years, charges China denies. Modi is expected to take a tougher stance with neighbouring countries, including China. In the first such signal, Modi’s government eased restrictions on building roads and military facilities along the border to boost defence preparedness and close the gap on China’s superior transport network.

VISAS – China often refuses to stamp visas on Indian passports from disputed territories and instead staples them to the page, a practice that infuriates India. China has refused to issue visas to Indians from Arunachal Pradesh state, where the two countries fought the 1962 war, saying they do not need permission to travel to China. China claims the whole of Arunachal Pradesh, which it calls “South Tibet”. In 2012, India started stamping its own map on visas it issues to holders of new Chinese passports that contain a map depicting disputed territory within China’s borders. The visa issue is likely to be on the agenda during Xi’s visit.

TRADE TIES – China is India’s largest trading partner, with two-way trade at about $66 billion last year. However, $51 billion of that came from Chinese exports. India hopes new investments from China will partly help offset its trade deficit. China plans to invest about $7 billion in two industrial parks in western India, media reported this month. India will also ask its neighbour to set up manufacturing units for exports as it seeks to revive its economy,

RAILWAYS – India has the world’s fourth-longest rail network but has added only 11,000 km of track since independence in 1947. China, in comparison, added 14,000 km of track in the five years to 2011. China is expected to pledge billions of dollars of investment in India’s rail network that can help reform the now-decrepit British-built system.

NUCLEAR TIES – In 2013, Chinese Premier Li Keqiang said the two countries would cooperate in civil nuclear energy. Leaders of the two energy-starved countries may discuss the possibility of a civil nuclear cooperation agreement, Indian officials said. China has committed $6.5 billion to finance the construction of a major nuclear power project in Karachi, the financial hub of neighbouring Pakistan, India’s traditional foe. But Beijing might make a push to supply India with its new-generation reactors, The Hindu newspaper said.