Washington: President Donald Trump told airline and airport executives that he is interested in privatising America's air traffic control system and improving the nation's airports and roads, which he called obsolete.

Trump also promised to roll back government regulations and said he will announce a plan in the next three weeks to reduce taxes on businesses. But he sounded skeptical about raising fees that airline passengers pay to fund airport improvements.

One issue was notably absent during the White House meeting Trump's executive order to temporarily ban travel to the US from seven mostly-Muslim countries.

Airline leaders had criticized the order, which is on hold while it is reviewed by a federal appeals court.

Airline and airport executives who emerged from the White House meeting called it a positive session.

Southwest Airlines CEO Gary Kelly told Trump the best way to help airlines would be to "modernize the air traffic control system." He complained that money spent on the system has not improved it.

"I hear we're spending billions and billions of dollars, it's a system that's totally out of whack," Trump said.

Some airline executives and Republicans in Congress have proposed privatising air traffic control because they say the Federal Aviation Administration has moved too slowly on modernisation and would benefit by being removed from the uncertain congressional budget process. Other lawmakers oppose reducing Congress' oversight of aviation, and business and private aircraft owners worry their costs will go up.

Nick Calio, president of Airlines for America, the trade group that represents most major airlines but not Delta, said Trump was "extraordinarily positive" when airline executives urged him to spin off air traffic control operations from the Federal Aviation Administration and place them under the control of a private, nonprofit corporation.

While Trump supported modernizing the air traffic system, he did not explicitly endorse privatization, said another participant, Kevin Burke, president of Airports Council International-North America.

Unlike the US, most countries separate air traffic control duties from their aviation-safety agencies. But it is unusual to actually privatise air traffic operations. Canada is an exception.