US State Department warns Americans of growing security risks in historic region

The agreement, however, remains uncertain. U.S. officials said Iran has not publicly released the draft language, and the arrangement would still leave major questions unresolved, including broader nuclear limits, sanctions relief and whether the pause in hostilities can hold.

In an early June security alert, the U.S. Embassy in Jerusalem said the security environment in the Middle East remains "complex" and could change quickly, urging Americans in the region to monitor breaking developments.

The latest diplomatic movement could affect travelers because the Strait of Hormuz has been a major flashpoint in the region. 

The advisories cover countries that are home to major cultural and tourist destinations, from UNESCO World Heritage Sites such as Persepolis in Iran, Babylon in Iraq, Palmyra in Syria and the Old City of Sana'a in Yemen to popular stops in Level 3 countries, including Petra in Jordan, Jerusalem's Old City and the Burj Khalifa in Dubai.

"Be aware of your surroundings," the alert warned. 

"Avoid all demonstrations and large gatherings."

Americans in the affected countries were also urged to avoid areas with a heavy police presence, follow the instructions of local authorities and "keep a low profile."

Notably, the release did not mention Egypt or Turkey, which both sit at Level 2, according to the State Department's website.

Authorities say the Trinidad and Tobago advisory was spurred by "a spike in violent criminal activity that could threaten public safety."