With less than two weeks left before he leaves office, Sen. Bob Corker stood his ground once again to denounce President Donald Trump's decisions — from the government shutdown to pulling U.S. troops from Syria.

Corker called Sunday the partial federal government shutdown an unnecessary action and a "made up fight" perpetrated by the president.

"This is a purposefully contrived fight," the Tennessee Republican said on CNN's "State of the Union" on Sunday morning.

On Thursday, Trump announced he wouldn't sign a Senate-approved budget deal to keep a number of federal departments funded through early February because it did not include $5 billion of funding for the construction of a wall along the U.S.-Mexico border. That led to the shutdown on Saturday.

With no signs of a deal, the Senate adjourned until after Christmas, ensuring that the shutdown would continue until least Dec. 27.

Corker said that Democrats and Republicans had supported legislation to provide $25 billion for border security while also dealing with young immigrants who arrived with parents who entered the country illegally. That legislation wasn't ultimately approved.

"At the end of the day, our borders will still be insecure," Corker said. "The president could have received $25 billion in (funding) in dealing with the DREAMers."

"Most Republicans want to deal with the DREAMers," Corker told CNN. "This is a made-up fight so the president can look like he’s fighting. Even if he wins, our borders won't be secure."

After Corker's criticism of the shutdown and Trump's decision to withdraw U.S. troops from Syria, the president fired back on Twitter Sunday afternoon.

He slammed Corker over his decision not to seek a third term, saying Corker "wanted to run but poll numbers TANKED when I wouldn't endorse him ..."

Corker quickly replied, seeming to imply that the president's statement was misleading by pointing to a certain Trump campaign promise.

"Yes, just like Mexico is paying for the wall... #AlertTheDaycareStaff," Corker tweeted.

Corker, who did not seek re-election in November, has had a tumultuous relationship with Trump over the past two years.

Corker has criticized the president's handling of a number of issues, and the two have traded barbs — including on Twitter — even as they have worked together on a number of domestic and foreign policy matters.

On Sunday, Corker went on to say that the reasoning for the shutdown was "juvenile."

"I want to see real border security and that’s why I am disappointed with this Congress," he said.

While senators are set to return to Washington after Christmas, the shutdown could stretch into the new year. Acting White House Chief of Staff Mick Mulvaney told "Fox News Sunday" that the negotiations over the border and spending bill aren't going to move quickly.

Mulvaney said "there's a chance this could go into the next Congress," which begins Jan. 3.

He said that the White House has made a counter offer and would reduce its demand from $5 billion. But he wouldn't specify an amount. Democrats have discussed only providing $1.3 billion.

What you need to know:The federal government is shut down. Here's what it would mean for Middle Tennessee.