ISLAMABAD - After peace talks between the United States and Iran concluded in Islamabad without an agreement, regional mediators are racing to secure a second round of negotiations within days to prevent the collapse of a fragile, two-week ceasefire, the Wall Street Journal reported Sunday, citing officials familiar with the matter.

The major sticking points include the reopening of the Strait of Hormuz without collecting transit fees, the fate of Iran's stockpile of highly enriched uranium, and Tehran's demand for the release of roughly $27 billion in frozen revenues.

Pakistani authorities, who hosted the initial session, are in active consultation with both Washington and Tehran to revive the talks before the ceasefire lapses. Despite the lack of a breakthrough, the Pakistani side remains cautiously optimistic about the prospects of continued engagement.

The primary objective is to "wrap it up before the deadline" - set for April 22 - to avert a return to open hostilities, a senior Pakistani source was quoted as saying.