India, April 20 -- In a sharp escalation of rhetoric ahead of a looming ceasefire deadline, Iran has refused to join the second round of negotiations, accusing Washington of making "excessive demands" and pursuing a contradictory approach while continuing a naval blockade it calls a violation of the truce.

The development comes even as US President Donald Trump announced that American negotiators will travel to Islamabad on Monday for fresh talks aimed at ending the ongoing conflict involving the United States, Israel and Iran.

Trump, in a social media post on Sunday, did not disclose the composition of the US delegation. A previous round of in-person talks in Islamabad, led by US Vice President JD Vance, ended without a breakthrough. ...