The request was made due to concerns that Iran could potentially launch a military operation in response to the new US sanctions that took effect on Monday, according to the CNN broadcaster.
Pentagon officials, however, have no intelligence information about possible Iranian retaliatory measures, the broadcaster added.
A new batch of sanctions, targeting Iran's oil trade, shipping and banking, came into being on Monday. US Secretary of State Mike Pompeo said earlier that Washington expected all countries to eventually reduce their oil imports from Iran to zero. At the same time, Washington temporarily exempted eight nations from the sanctions on importing oil from Iran.
In May, US President Donald Trump announced that the United States would withdraw from the Iran nuclear agreement or the Joint Comprehensive Plan of Action (JCPOA) and re-impose sanctions against Tehran that were lifted under the accord. The first round of US sanctions were imposed in August.
More about: US Persian-Gulf Iran sanctions
