Washington: The U.S. Navy’s forcible seizure of an Iranian-flagged cargo ship has cast doubt on President Donald Trump’s announcement that U.S. negotiators would head to Pakistan on Monday for another round of talks with Iran.

Trump’s announcement Sunday had raised hopes of extending a fragile ceasefire set to expire by Wednesday.

Iran’s Foreign Ministry spokesperson, Esmail Baghaei, said Monday that Tehran did not yet have plans to attend any talks with the United States.

Trump said the U.S. seized the cargo ship after it tried to circumvent a naval blockade near the Strait of Hormuz on Sunday, marking the first such interception since the blockade of Iranian ports began last week.

Iran’s joint military command said Tehran would respond soon and called the U.S. seizure an act of piracy.

The escalating standoff threatened to deepen the energy crisis roiling the global economy and push the two countries toward renewed fighting.