How navies track distant foreign warships

How would navies monitor Iranian warships crossing the South Pacific?

Maritime patrol aircraft, a Littoral Combat Ship, or another surface vessel could keep track of them. The particular assets involved are not identified.

A reported transit by two Iranian warships near French Polynesia prompts an assessment of how nearby navies could follow them. Maritime patrol aircraft, a Littoral Combat Ship, or another surface vessel could provide surveillance. Comparable monitoring accompanies Russian warships near Britain. The suggested assets illustrate possible ways to maintain contact; no particular ship or aircraft is confirmed as following the Iranian vessels.