By David D. Kirkpatrick

New York Times News Service

LONDON — Three Iranian boats Thursday briefly tried to block passage of a British tanker in the Strait of Hormuz, Britain’s Defense Ministry said, in the latest sign Tehran is seeking any pressure point it can exploit in its escalating confrontation with the West.

The tanker, British Heritage, was under escort by a warship, the Montrose, and after a brief standoff but no exchange of fire the three Iranian boats complied with “verbal warnings” to retreat, the ministry said.

The latest showdown occurred less than a month after the downing of a U.S. surveillance drone by the Iranian military brought the United States to the brink of a retaliatory missile strike, aborted by President Donald Trump only moments before launch.

Iran denied having attempted to stop the tanker, official news agencies reported.

But as recently as last Friday, a senior Iranian military officer had warned that its forces might try to seize a ship in retaliation for the British impounding of an Iranian tanker last week off the coast of Gibraltar. The tanker was suspected of violating a European Union embargo of oil sales to Syria.

In a statement about the latest incident, BP, the oil giant that operated the ship, thanked the British Royal Navy “for its support.”

At the core of the broader confrontation with Iran is the Trump administration’s decision last year to repudiate a 2015 accord Iran reached with the United States and other international powers. The agreement called for Iran to suspend and dismantle most of its nuclear program in exchange for relief from international economic sanctions.

Demanding that Iran submit to far more sweeping restrictions on its nuclear, military and other activities, the Trump administration last year began a new campaign of “maximum pressure.”

The Iranians appear intent on putting their own pressure on the United States and its allies by pushing back on at least two different fronts.

In its most public response, Iran has taken carefully calibrated steps to revive its nuclear program. President Hassan Rouhani has come close to taunting Western officials with threats that Tehran could soon restart precisely the nuclear programs the West had deemed a menace.