3-D Secure (3DS) is an extra layer of authentication controlled at the merchant level (e.g. through a Stripe checkout) that a user may be required to pass before completing a transaction. 3DS is called Visa Secure, SecureCode, or SafeKey by Visa, Mastercard, and American Express respectively.
Because a very small percentage of U.S. merchants (less than 1%) enforce 3DS, our processors and bank partners choose not to support them. This technology is more readily enforced by EU based merchants. It also creates more friction at the checkout for users, and more declined transactions for merchants.
If this causes an inconvenience for your users, please let us know. If there is a large enough demand, we can inquire with our processor partners and bank partners to support 3DS in the future.