US secretary of state Rex Tillerson has laid out a strategic vision of a closer military, trading and diplomatic partnership with India to last 100 years as a bulwark against China, two weeks before Donald Trump is due to make his inaugural trip as president to Beijing.

The US, which unveiled its new south Asia strategy after months of deliberations in August, has built up India’s role as a potential solution to both its longest running war in Afghanistan and concerns over the rise of China. 

“We think we have wisely chosen a partner in India for a strategic relationship,” Mr Tillerson told a gathering at the Center for Strategic and International Studies. He noted the Trump administration’s determination to “dramatically deepen” relations with India, which he said could become the world’s second-biggest economy by 2050 and surpass China’s population within 10 years.