WASHINGTON, April 16 --   The United States is discussing a possible second round of peace talks with Iran in Pakistan and is optimistic about reaching a deal, US officials said yesterday, as Tehran threatened to shut down Red Sea trade unless Washington lifted a naval blockade of its ports.

A Pakistani delegation arrived in Tehran meanwhile bearing a new message from Washington after US President Donald Trump indicated negotiations could resume this week following last weekend's abortive talks in Islamabad.

White House Press Secretary Karoline Leavitt told reporters further talks "would very likely" be in the Pakistani capital. "Those discussions are being had," Leavitt said, and "we feel good about the prospects of a deal."

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