Transferring funds to my USC spouse from outside the country as a non-resident: Tax implications?

Hello everyone!

Sorry if this post doesn't align with the spirit of this subreddit. If so, please suggest where I should post instead.
I'm exploring the option of sending a significant amount of money to my spouse in the US using cryptocurrency (thinking about USDT). As a non-resident living outside the US, I have a few questions:

Are there any US gift tax implications for sending crypto to a US citizen spouse? How does it work for non-residents?

I'm also interested in understanding the most efficient way to transfer crypto in this context. Any insights on minimizing fees and ensuring a smooth transaction would be appreciated.
I could send it through conventional means like SWIFT but the fees are around 5% and I wanted to see if there are more cost-efficient solutions.

Thank you!