The Trump administration is withholding military assistance to Lebanon following the resignation of the country's prime minister amid weeks of protests.

Two U.S. officials told Reuters that the State Department had informed Congress of the decision, though no explanation was given for the holdup, according to one official.

The State Department did not immediately return a request for comment from The Hill.

While the reason for the freeze on military aid was unclear, U.S. officials have reportedly shown concern about the growing role in the country of the Iran-backed political party Hezbollah, which is designated as a terrorist group by the U.S.

Lebanon has been rocked by weeks of protests, with demonstrators shutting down major roads over allegations of widespread corruption in government and a newly announced tax on calls made using Whatsapp and other messaging services.

The country's prime minister, Saad al-Hariri, resigned on Tuesday, and Secretary of State Mike PompeoMichael (Mike) Richard PompeoPompeo says Trump-Zelensky call was 'consistent' with administration policy Giuliani hits back at Trump's nominee for Russia ambassador: He 'doesn't know what he's talking about' NY Democrat presses Trump officials on terrorist designation for foreign white supremacist groups MORE has reportedly urged the country's leaders to form a new government quickly.

One U.S. official told the news service that the withdrawal of the U.S. security assistance would likely result in Russia moving in to offer aid in response, driving Lebanon's government closer politically to the Kremlin.