Traveling internationally with encrypted data you don't want to disclose to border officials is not a good plan these days. Much safer to transfer securely via network connection.

It's easy to single out the US but the reality is that most countries have pretty far reaching rules these days. E.g. the UK and Australia are hardly any safer. And forget about China, Russia, or indeed most countries with even less democratic regimes.

The bottom line is that if you are not willing to unlock your device at any of the security checkpoints you will pass on your journey, you should leave it at home or just wipe it preemptively and restore over a secure connection after you arrive. In case it does get unlocked or taken from you, consider the device burned. It may come back to you with all sorts of malware. The people doing this are not thinking you are a terrorist or a child pornographer: you are being targeted and under attack by a hostile entity. Assuming otherwise would be a mistake. Wipe it, sell it on e-bay, never use it again.