His comments come after a recording emerged of the moments before a UK-flagged oil tanker - the Stena Impero - was seized.
The DFA said Philippine Ambassador to Iran Fred Santos was contacting Iranian authorities to seek assurance that the Filipino seafarer is safe and will be released soon.
Earlier on Sunday, Iran said that it launched a maritime casualty, accusing the Stena Impero's crew of ignoring a distress signal after an "accident" with an Iran shipping boat.
"All its 23 crew members will remain on the ship until the probe is over", Allahmorad Afifipour was quoted as saying by Iran's Fars news agency.More news: Hundreds rally for 'martyrs' in Sudan
Its crew is made up of 18 Indians, including the captain, three Russians, a Latvian and a Filipino.
"The investigation depends on the cooperation by the crewmembers on the vessel", he told Press TV.
In a letter to the UN Security Council, Britain said the tanker was approached by Iranian forces when it was in Omani territorial waters exercising its lawful right of passage, and the action "constitutes illegal interference". Filmed from a ship and a helicopter, it shows small craft sailing alongside the ship, troops in balaclavas inside a chopper, and six people descending down a rope onto the vessel.
Tehran has been at loggerheads with Washington since May 2018, when President Donald Trump unilaterally withdrew the U.S. from a landmark 2015 deal putting curbs on Iran's nuclear programme in exchange for sanctions relief.More news: Loki Disney+ Series Confirmed for Spring 2021 Release
British Foreign Secretary Jeremy Hunt is expected to announce on Sunday diplomatic and economic measures, including potential asset freezes, as a response to the incident, according to a report in the London Daily Telegraph.
This is the latest in the string of maritime episodes involving Iran since tensions with the United States escalated in June.
The oil tanker was impounded off Bandar Abbas port hours after a court in the British overseas territory of Gibraltar said it would extend by 30 days the detention of Iranian tanker "Grace 1" seized by British authorities in the Mediterranean two weeks ago on allegations of breaching European Union sanctions against Syria.
Britain summoned Iran's charge d'affaires on Saturday and urged his country to de-escalate tensions and release the tanker.More news: SDCC 2019: Supergirl Season 5 Trailer
On Sunday junior defence minister Tobias Ellwood told Sky News that Britain was "going to be looking at a series of options", without giving further details. Dijo joined the crew of Steno Impero a month ago.