It’s just a narrow body of water. You would have to assign the territory by lat/longs.
President Trump stated that he will declare the Strait of
Hormuz “US territory” after the conflict with Iran concludes.
However, apparently legally..... and logistically...... a US president cannot unilaterally claim an international waterway bordered by sovereign nations as “American territory.” -——The Guardian
Yet, Iran cannot legally stop a unilateral US political declaration,
but it can physically and strategically contest American control:
<><>through military posture,
<><>regional partnerships,
<><>and choke-point leverage.
Whether President Trump’s threats translate into formal
“territory status” remains legally and practically ambiguous.