China's massive Belt and Road infrastructure program should only go where it is needed and where the debt it generates can be sustained, International Monetary Fund Managing Director Christine Lagarde said.

Lagarde said the program to build ports, railroads and other trade-enhancing infrastructure was having a positive impact on growth in certain countries but needed to be managed carefully.

She called for a revamped "Belt and Road 2.0" to include increased transparency, an open procurement process with competitive bidding and better risk assessment in project selection.

Lagarde said that Chinese authorities were taking positive steps with a new debt sustainability framework that will be utilized to evaluate projects.