The Iranians have closed the Strait because the blockade is still continuing. If there is a ceasefire within the region there is no need to continue the blockade, particularly if you want the Iranians to negotiate.
In addition, there was talk of negotiations taking place this weekend but as of today, nothing has been planned.
Trump also claimed that Iran had “agreed to everything,” which Iran quickly denied, saying it had not agreed to anything.
This is fairly typical for US foreign policy as it is now being “run.”