BEIJING, March 28 -- The connectivity of infrastructure is a priority for implementing the Belt and Road Initiative, according to an action plan unveiled Saturday.

"Countries along the Belt and Road should improve the connectivity of their infrastructure construction plans and technical standard systems, jointly push forward the construction of international trunk passageways, and form an infrastructure network connecting all sub-regions in Asia, and between Asia, Europe and Africa step by step," the plan said.

The action plan, with the title of Vision and Actions on Jointly Building Silk Road Economic Belt and 21st-Century Maritime Silk Road, was released Saturday by the National Development and Reform Commission, Ministry of Foreign Affairs and Ministry of Commerce.

The Belt and Road Initiative was first proposed by President Xi Jinping in 2013 to connect Asian, European and African countries more closely and promote mutually beneficial cooperation.

"At the same time, efforts should be made to promote green and low-carbon infrastructure construction and operation management, taking into full account the impact of climate change on the construction," the plan read.

With regard to transport infrastructure construction, countries should focus on the key passageways, junctions and projects, and give priority to linking up unconnected road sections, removing transport bottlenecks, advancing road safety facilities and traffic management facilities and equipment, and improving road network connectivity.

Those countries should also expand and build platforms and mechanisms for comprehensive civil aviation cooperation, and quicken the pace in improving aviation infrastructure.

The plan also emphasized the connectivity of energy infrastructure, saying that countries should work together to ensure the security of oil and gas pipelines and other transport routes, build cross-border power supply networks and power-transmission routes and cooperate in regional power grid upgrading and transformation.

The countries should jointly advance the construction of cross-border optical cables and other communications trunk line networks, improve international communications connectivity to create an Information Silk Road.

"We should build bilateral cross-border optical cable networks at a quicker pace, plan transcontinental submarine optical cable projects, and improve spatial (satellite) information passageways to expand information exchanges and cooperation," the plan said.