Washington - A Syrian military intervention into Lebanon following a series of terrorist attacks would be "unacceptable," the US State Department said Monday.

The Syrian government has reportedly amassed thousands of soldiers near the border area in north Lebanon, prompting worries in Beirut that Damascus was preparing for an incursion.

State Department deputy spokesman Robert Wood said the September bombing attacks in Damascus and the Lebanese city of Tripoli cannot be used as a pretext for military intervention.

"The recent terrorist attacks ... should not serve as a pretext for ... further Syrian military engagement - or should not be used to interfere in Lebanese internal affairs," Wood said.

Northern Lebanon has also been the site of sectarian clashes in the last few months. The Syrian government said the deployment of the troops was to improve border security.

Syria ended a three-decade occupation of Lebanon in 2005 following the assassination of former Lebanese prime minister Rafik Hariri, an opponent of Syrian meddling in the country.

The assassination was largely blamed on Syrian intelligence and renewed international pressure, led by the United States and France, on Syria to withdraw. (dpa)