Sources in Iraq and the U.S. told The New York Times that the United States aims to enhance the economic isolation of Iran by sealing its land borders with adjacent nations.

According to the sources, U.S. officials have been trying for weeks to diplomatically persuade Iran’s neighboring nations to close their border crossings but have not succeeded.
Yet, Iran’s neighboring countries, particularly Turkey, Iraq, and Pakistan, have become more cautious and discontent with U.S. policy, worried that it might harm them as much as it would harm Tehran, the sources indicated.
One source suggested that these countries are apprehensive about a “civil uprising” if they try to impede trade routes crucial for businesses and communities on either side of the borders.
On November 7, the U.S. armed forces became part of the diplomatic initiative, declaring the establishment of “Task Force Iron Gate. The NYT mentions that, from Washington’s perspective, Task Force Iron Gate and the sealing of land borders would make additional attacks on Iran unwarranted.
source: nytimes.com