Heard this from a friend who has foreign currency accounts with Citibank. He said the debit card can be switched/linked to to a FCA.

By default, the debit card is linked to MYR current/saving account.
However, you can call customer service to switch the debit card to a FCA , i.e. USD account, just before your travel or online purchase. You need call CS to switch the card back to MYR account later. Need to maintain at least $3000 or equivalent in FCA to avoid monthly fee though.

TransferWise could be a better option. There are already many threads on TW here under Finance, Business and Investment section.