WASHINGTON, March 21 (Reuters) - Transportation

Secretary Sean Duffy will unveil a plan next week to upgrade the

aging, under-staffed U.S. air traffic control system next week,

he said on Friday.

Duffy said earlier this month that he planned to ask

Congress for tens of billions of dollars for a multi-year effort

to revamp air traffic control and boost hiring after a series of

aviation safety incidents raised alarm. Duffy said on Friday

that he had briefed President Donald Trump, who wants "to create

a state-of-the-art, brand new air control system" and supports

the plan.