Sri Lanka slammed China's ambassador on Tuesday for criticising Colombo's attitude to aid in the local media, as the island nation distances itself from its once-close ally and economic lifeline.

Colombo took exception to ambassador Yi Xianliang's comments at a press conference last week, where he said his host nation should stop criticising "expensive" loans granted by Beijing for infrastructure.

The new government, which came to power in January last year, has been trying to renegotiate the terms of its $8 billion Chinese debt -- a hangover of the former regime's heavy reliance on Beijing.

"I note some media, even some ministers, say expensive loans (were given) from China. No, this is really unfair for (the) Chinese government," Yi said, according to a video of the press conference posted on social media.

"Sri Lanka people and the government should have some attitude in thanks giving," he added, apparently suggesting Colombo should be grateful for Beijing's economic largesse.

Sri Lankan Foreign Secretary Esala Weerakoon telephoned ambassador Yi on Monday to express Colombo's displeasure.

"It was explained to the ambassador... that it is not necessary for the ambassador to communicate his concerns through the media," the ministry said in a statement.

Former president Mahinda Rajapakse relied heavily on China to build ports, highways and railways as Western nations shunned him over his dismal human rights record.

But President Maithripala Sirisena's government suspended all Chinese-funded infrastructure projects shortly after taking power, accusing the previous regime of corruption.

Colombo secured a $1.5 billion bailout from the International Monetary Fund in June after facing a balance of payments crisis. It has also negotiated cheaper funding from international lenders.