expression
no matter what; whatever happens; come what may
Emphatic expression meaning 'regardless of what occurs'; similar to 何があっても but with a slightly more formal or literary feel.
See also: 何があっても
何があろうと、私はあなたの味方です。
No matter what happens, I'm on your side.
何があろうと、この計画は実行する。
Whatever happens, we will carry out this plan.