You have to go though several test in order to be posted in US.
As you know their system are slightly different from us.

And ya, IMU degree is worldwide recognize.
Not that certain universities are yet to register with MQA or edu board.

If you wants to save money, do locally.
You can choose to do your postgraduate overseas, which will be better than doing it in Malaysia. A lot of my seniors choosing this path. Graduate from IMU, then went to UK for specialization.

Note that I'm not medic student nor sciences.
But I still know all these stuff. I once applied, but changed my mind

If you really can't make decision, just call them out and postponed the dateline. They wouldn't mind

AFAIK, anyone regardless of what degree you have including IMU's, you can go sit for the US USLME medical examination. If you pass, you can apply to work in US and I presume, specialization as well.