The World Trade Organization's top official told CNBC that Europe and the United States should sit down and negotiate a solution to subsidy disputes involving Airbus and Boeing.

Last week, arbitrators from the WTO granted President Donald Trump's administration the right to levy billions against imports of European goods for what they say are illegal subsidies granted to planemaker Airbus by the European governments of Germany, France, Spain, and the United Kingdom.

Trump subsequently described the ruling as a "nice victory."

https://twitter.com/realDonaldTrump/status/1179697599143653377

The EU has its own separate case before the WTO, in which it argues that the U.S. planemaker Boeing receives unfair financial assistance from the U.S. federal government.

The EU has said it wants to agree on a way forward with Washington by imposing a new regime on aircraft subsidies.

Director general of the WTO, Roberto Azevedo, told CNBC’s Joumanna Bercetche in Geneva Thursday that he hoped both sides would agree to conduct talks.

"I hope parties will sit down and talk and find a negotiated solution because the last thing we need at this point in time is an escalation of tariff barriers and trade restrictions," said Azevedo.

The WTO boss said slapping tariffs on imports tended to generate a "domino effect" of barriers to trade.

"You cannot expect that you can impose tariffs and barriers and everyone else is going to sit down and applaud quietly. They are going to respond," he said.