From January 1, all airlines using EU airports are obliged to acquire carbon allowances under the EU Emissions Trading Scheme (ETS). The law has triggered international protest from nations including the United States, China and India.

The following looks at what the meeting on Tuesday and Wednesday could decide and what might happen next.

WHAT'S ON THE AGENDA?

The Moscow agenda is expected to debate a range of possible counter-measures, ranging from a formal dispute at the U.N.'s International Civil Aviation Organization (ICAO) to blocking legislation banning airlines from participating in the EU's ETS to retaliatory fees for EU flights.