Jack Lew, US Treasury secretary, called on Beijing to “renew” a pledge to overhaul its exchange rate policy on Tuesday, in his first visit to the Chinese capital since the renminbi began to reverse its long climb against the dollar earlier this year.

The renminbi has weakened about four per cent against the dollar since January, ending a four-year trend during which China’s currency appreciated almost 12 per cent against the US dollar. The renminbi trades at Rmb6.24 to the dollar, after flirting with the Rmb6 level earlier in 2014.

“It is important that China demonstrate a renewed commitment to move to a more market-determined exchange rate which will help provide for more balanced domestic growth and global trade, while also moving to a more transparent exchange rate policy,” Mr Lew said in comments ahead of a meeting with Chinese vice premier Wang Yang.