According to the New York Times, Turkey, Iraq and Pakistan are not fully cooperating with the United States' request to close the border crossings with Iran. These countries fear that restricting trade with Iran will also harm their economy and internal security.
During the last few weeks, American officials tried to convince Iran's neighbors to close the border crossings, but so far they have not achieved the desired result. Turkey has largely refused to change its border policy, and Iraq has not accepted Washington's request to close all but two border crossings with Iran. However, Baghdad has temporarily closed some crossings and Pakistan has opened and closed several of its border crossings in recent weeks.
According to this report, the US military announced the establishment of a special force called "Iron Gate" whose stated mission is to prevent the transfer of advanced weapons, dual-use technologies, sanctioned goods and illegal income from Iran's land borders and the Caspian Sea.