Secretary of State Mike Pompeo warned the Lebanese government during his recent visit to Beirut that Hezbollah and Iran have set up a new covert factory for precision missiles on Lebanese soil, U.S. sources briefed on the matter tell me.

Why it matters: The sources say Pompeo based his warning on intelligence he received from Israel. Israel is greatly concerned about Hezbollah's manufacturing of precision missiles but hasn't responded with military force out of concern that could lead to an all out war.

The backdrop: Last September at the UN, Israeli Prime Minister Benjamin Netanyahu revealed satellite imagery of what he claimed were two covert Hezbollah sites for manufacturing precision missiles. A few weeks later, Hezbollah shut down the sites. Now it seems Hezbollah and Iran have opened a new factory.

Pompeo visited Jerusalem two weeks ago and met with Netanyahu, who presented him with intelligence which pointed to a new covert facility in Lebanon, the U.S. officials say.

From Jerusalem, Pompeo traveled to Beirut. The U.S. sources tell me Pompeo met with Lebanese Prime Minister Saad Hariri and warned him that the existence of the new covert missile facility could have consequences for Lebanese security.

According to the sources, Pompeo told his Lebanese counterparts that Hezbollah's covert operations in Lebanon raise the risk of a real escalation with Israel. Pompeo wanted to make sure that all the information he had about Hezbollah's activities was also known to the Lebanese government, the sources say.

The State Department told me: "We do not disclose the contents of private diplomatic talks."