China will take swift counter-measures that could include impounding European aircraft if the EU punishes Chinese airlines for not complying with its scheme to curb carbon emissions, the China Air Transport Association said on Tuesday.

The warning came as the UN's aviation body expressed concern about the growing threat of bilateral reprisals.

Chinese airlines, which have been told by Beijing not to comply with the European Union's Emissions Trading Scheme, refused to meet a March 31 deadline for submitting carbon emissions data.

A new stand-off looms after EU Climate Commissioner Connie Hedegaard said the carriers would have until the end of this week to submit their data or face enforcement action.

'Chinese airlines are unanimous on this. We won't provide the data,' Wei Zhenzhong, secretary general of the China Air Transport Association, said on the sidelines of an International Air Transport Association (Iata) meeting in Beijing.

EU member states can fine airlines for non-compliance or carry out other reprisals including impounding aircraft. 'We would not like to see a situation of 'you hold up my planes and I hold yours',' Wei said.

The Chinese airline group's members include the big three state-controlled carriers - Air China , China Southern Airlines and China Eastern Airlines .

'The government will take at least the same kind of measures, and these anti-sanction moves will be lasting,' Wei said. He added, however, 'We would try to avoid any trade war.'

China is among a raft of countries including India, Russia and the US that have protested against the inclusion of all flights using EU airports into the emissions scheme.

The EU's cap-and-trade scheme will effectively in most cases charge airlines for emissions based on the length of the whole flight, rather than just the portion flown over Europe.

Critics say this amounts to interference with non-EU airspace. The EU says such action is needed to meet the bloc's environmental targets and fill a vacuum left by international failure to deal with aviation emissions.

The head of the United Nations agency responsible for seeking a global solution to the row expressed concerns over the dangers of tit-for-tat retaliation between Europe and China.

'We are very concerned about what is happening with Europeans and China - retaliatory measures. We are very concerned about that, because we want air transport to continue growing,' the International Civil Aviation Organization's (ICAO) president, Roberto Kobeh Gonzalez, told Reuters.

Most countries involved in the dispute are looking to ICAO to come up with a global plan, but preliminary technical talks have proved complicated, and some nations are seen as unwilling to negotiate under what they see as pressure from the EU. - Reuters