If You Purchased the Ring in the U. S. and Plan on Bringing It Abroad and Back with Modifications, There Is No Need to Declare the Ring as It Is Considered a...
If you purchased the ring in the U.S. and plan on bringing it abroad and back with modifications, there is no need to declare the ring as it is considered a personal good. However, if you are worried about being questioned, it may be a good idea to register the ring before you go abroad.
Will an engagement ring go through airport security?
Most of the time you'll be asked to clear your pockets of any objects as you go through airport security....so hiding the ring there temporarily is not the best idea. Having the ring tucked away in your bag won't set off any alarms, but there's always the chance your bag can get searched.
Do you have to take your engagement ring off at the airport?
You don't need to remove any jewelry when going through airport security. However, if you trigger an alarm going through the metal detector you might need to undergo “additional screening”. In the United States, this usually takes the form of a physical pat-down from the Transportation Security Administrator officer.