Preparations for the second round of US-Iran talks have entered their final phase in the Pakistani capital, Islamabad. American advance teams continue to arrive ahead of the start of formal consultations, official sources said, reports The Express Tribune.

According to these sources, 11 aircraft carrying personnel, equipment, and vehicles arrived in Pakistan from Sunday to Monday evening. Most of the preparatory teams are already in place, and the main delegations are expected by Tuesday. The Iranian side may arrive in the Pakistani capital on Tuesday evening.

Pakistani authorities have not officially commented on the situation, but sources report that there are major uncertainties around the positions of the parties. Diplomatic channels between Washington and Tehran, according to them, remain open.

Security for these talks has been beefed up, with more than 18,000 law enforcement officers deployed.

According to CNN, the second round of talks is scheduled for Wednesday morning of April 22. Iran had previously said that a final decision on whether to participate in the talks had not yet been made.