(CNN) The Trump administration has lifted a mysterious hold on security assistance to Lebanon , which includes a $105 million package to support the Lebanese Armed Forces , according to a senior State Department official and a congressional aide.

The money had been held up by officials at the Office of Management and Budget for months, even though it had been approved by Congress and had strong backing from the State Department, Pentagon and officials at the White House's National Security Council.

Pentagon and State Department officials as well as national security experts said the military assistance, which covers the cost of US-made military equipment supplied to the Lebanese army, was crucial for maintaining stability in the country and pushing back against Iran, which the Trump administration says is a foreign policy priority.

A senior State Department official maintained the Trump administration silence over the precise reason for the hold on Monday, refusing to discuss why the freeze had been in place, why it had been lifted or who made the decision to end it. That official simply cited the "process" and said they would like to comment, but could not.

'No legitimate ... rationale'

But that official stressed the importance of the Lebanese Armed Forces as a national institution.

"This is ... a national institution. It defends the Lebanon borders, it is an excellent partner to the United States in counterterrorism and fighting Sunni Jihadi Islamists. They have developed in recent years high level capabilities in that regard," the senior State Department official said, adding that the Lebanese military has responded in an "impressive fashion" in recent weeks to large protests.

Sen. Chris Murphy, a Connecticut Democrat who traveled to Lebanon last week, said he had walked away convinced of the necessity of the US support for the Lebanese Armed Forces. Murphy said Monday that he is "relieved" the hold has been lifted, but raised questions about why it was put in place at all.

"There was no legitimate security rationale to withhold funding, and lots of reasons why withholding aid would actually hurt US interests. But the administration alarmingly decided to delay these funds without explanation and did so at the worst possible time," Murphy said. "In contrast to the violent response to other protests sweeping the region, the LAF has stepped up to protect demonstrators and defend the democratic rights of Lebanese citizens. They deserve our respect and strong support at this critical moment."

Lawmakers and analysts were highly critical of the hold and drew comparisons to President Donald Trump's move to freeze aid to Ukraine, which has drawn scrutiny because of the impeachment inquiry into Trump's possible use of aid as leverage to demand an investigation into his leading Democratic rival in the 2020 presidential race.

In November, fresh off a trip to Ukraine, Murphy tweeted at length about the hold, saying that "just like w the Ukraine aid, Trump has given Congress no reason for the funding hold." Murphy said that some say Trump wants to cut off funding because the militant group Hezbollah "still has influence in Lebanon. This is true, but they have the least influence in the" Lebanese Armed Forces, which Murphy called "the counterweight to Hezbollah."

The aid freeze is "the dumbest thing we could do if we are trying to weaken Hezbollah," Murphy said. "As stopping Ukraine aid helped Russia, here the hold empowers Iran to step into the vacuum. And it could lead to the collapse of the country which would be a national security disaster."

'Ukraine again'

"The bottom line is simple: (1) in a way this is Ukraine again - it's not legal for Trump to hold funding that Congress authorized," Murphy wrote. He added that "whatever his reason, defunding the Lebanese military does the exact opposite of our policy goals, and signals another abandonment of a key ally."

Along with lawmakers, even State Department officials said they were given no explanation for the aid freeze, which some pro-Israel lawmakers had pushed for, arguing that the Lebanese military has been infiltrated by Hezbollah.

David Schenker, the assistant secretary of state for near eastern affairs, told reporters last week that the review was working its way "through the bureaucratic process." He never gave an explanation for the hold.

David Hale, a senior State Department official who testified on Capitol Hill as part of the Ukraine impeachment inquiry, said last month that the decision to release the Lebanese aid rested in the hands of OMB and that he had learned of the hold in late June.

Hale said State wasn't given a formal reason for the hold by OMB and pointed to "differences in opinion" between OMB and the administration's national security apparatus, which backs the importance of funding the Lebanese Armed Forces.

OMB has not replied to numerous requests for comment about the reason for the hold. A senior administration official told CNN on November 2 that "we have no decision to announce at this time, nor do we comment on internal deliberations."

There are questions over whether the holdup in the assistance was at all linked to an American citizen, Amer Fakhoury, who is detained in Lebanon. A Senior State Department official would not say if the case of Fakhoury and the hold on the US security assistance were related -- but did say that the two issues have been "periodically" linked at times in the past.