What triggered the resumption of US-Iran talks in Doha, and what immediate agreement preceded them?

The resumption of US-Iran talks in Doha was triggered by Iran's request for a meeting, as stated by President Trump on Truth Social, and followed an agreement by both sides to halt a series of tit-for-tat attacks over the Strait of Hormuz. A US official confirmed that both sides would stand down temporarily, allowing vessels to move freely through the strait again.

Why are US, European, and Gulf Arab nations concerned about potential fees for using the Strait of Hormuz, and what is Oman’s position?

US, Europe, and Gulf Arab nations are concerned because charges for using the Strait of Hormuz would likely increase energy costs and set a precedent for other strategic waterways; US Secretary of State Marco Rubio called any tolls or fees 'unacceptable'. Oman has told European officials there is 'no way of going back to the pre-war status quo' and ships may have to be charged some fees, though Omani officials publicly affirm they will abide by international maritime law.