AUSTIN -- Texas National Guard troops have been patrolling the state's border with Mexico since July, but the money to pay for them will run out in March. Several Republican lawmakers gathered Tuesday to say it's too early to send them home.

Since coming under the crosshairs of a massive border surge, apprehensions of undocumented immigrants have fallen from a peak of more than 6,600 per week in June to a steady average of 1,700 per week since September. The number has remained relatively static since then.

"The word got out that Texas was serious about securing our border," Lt. Gov. Dan Patrick (R-Texas) claimed at a Tuesday media conference to discuss the next phase of funding. Border security was a key pillar of Patrick's campaign, and he has vowed to make the issue a top priority in office.

Responding to a surge of children smuggled from Central America, then-Governor Rick Perry ordered 1,000 National Guard troops deployed to the Rio Grande Valley region in July 2014. Tasked primarily with border reconnaissance and providing a "show of force," the troops joined Texas Department of Public Safety (DPS) forces already deployed as part of Operation Strong Safety.

The combined operational cost was estimated at roughly $17 million a month, which Perry said would be paid from unexpended state funds. According to Patrick's office, the deployment was reduced to 200 troops in January 2015. The Texas Military Department estimates 400 to 500 troops would most efficiently serve their operational purpose.

Now the money is running out.

The legislature must decide by March 1 whether to approve more funding or pull out all remaining Texas National Guard troops by March 31. Backed by Republican colleagues in the Texas Senate, Patrick announced Tuesday he was tabling the idea. While crediting the operation for the drop in apprehensions, Patrick warned the border was "not yet secure."

"Because of the success, now is not the time to remove the National Guard from the border," said Patrick, who suggests a $12 million supplemental appropriation will keep the deployment funded through May -- long enough for legislators to approve a full budget which includes a historic $815 million border security package.

It would be enough to keep Texas National Guard troops on the border for another two years.

"We may not need the Guard to stay for the full two years," said Patrick. "We don't know what that strength will be. We leave that up to the professionals in law enforcement, but we have to have the funding in place and we cannot pull back now."

"The long-term plan, of course, is to draw down the Guard and replace them with more DPS officers, but that will take time," Patrick later added.

Patrick lists cartel crime and the possibility of terrorists crossing the border as major reasons for continuing the surge, and said he expects another surge in crossings in the spring and summer in response to the president's immigration policies.

According to DPS, $139 million in illegal drugs have been seized since the surge began in June 2014, yet only 427 cartel-related arrests have been made since 2007.

"Texas taxpayers are having to bear the brunt of this because the federal government is not doing their job," said Patrick, who left without taking a single question from the dozens of media outlets present for the pitch.

Patrick's counterpart across the rotunda, Texas Speaker Joe Straus (R-San Antonio), responded to the lieutenant governor's request to extend the guard's mission Tuesday afternoon.

"I appreciate Governor Patrick's remarks, but Governor Abbott is the Commander in Chief and he will decide whether to extend the National Guard's deployment," said Straus.

After the press conference, state Sen. Juan "Chuy" Hinojosa (D-McAllen) pointed out that while helpful to an extent, the National Guard isn't allowed to make arrests or carry out the duties of licensed peace officers. He argues state funding would go further if spent on local police and Texas Game Wardens, which perform actual law enforcement activities.

"We can make better use of those funds by focusing on our law enforcement that is effective," said Hinojosa. "At the same time I know the National Guard has certain assets that are very useful in coordination with local enforcement. We want to maximize those assets."

Before a meeting to brief media on an immigrant rights rally scheduled for Wednesday, Alejandro Caseres of the Austin Immigrant Rights Coalition took issue with Patrick's framing of the apprehension numbers.

"They weren't apprehending more people last year, people were turning themselves in because they were seeking refugee status," said Caseres, who added the region's legal residents are also becoming fearful.

"It's a scary situation when they see their borders being militarized and their homes are being militarized, that their constitutional rights are being violated, that they're being pulled over and asked for their documents status," said Caseres. "Some of these folks have been there for generations and generations."

It's a debate we'll be keeping close eyes on.