Vice President Joe Biden is reportedly close to a decision on a presidential run. But as the clock ticks, the challenges only increase for a national campaign.

With a little more than three months until Iowans head to their caucus sites, there is little time to play catch-up to Hillary Clinton and Vermont Senator Bernie Sanders, the front-runners in the Democratic race.

A top adviser to Biden, Ted Kaufman, acknowledged as much. In a memo to friends and former Biden staff Thursday night, Kaufman gave a nod to the challenges that lay ahead should Biden jump in.

“If he decides to run, we will need each and every one of you — yesterday!” Kaufman wrote.

One challenge Biden will face is in the fundraising arena. Clinton and Sanders raised nearly $30 million in the last quarter each. They've used that money to build a campaign team, travel around the country campaigning and raise money. And more importantly, they have a total of $60 million cash on hand — a good chunk of change, especially compared to Biden's empty purse.

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Biden also has logistical challenges. Each state posts different requirements for even getting a candidate's name on the ballot for the primary. Requirements include fees, signatures, statements, and sometimes all three. It takes teams of lawyers and advisers to figure it out and get it right. And he's running out of time. The first filing deadline is Georgia's, which is October 29. Quickly following is Alabama, Arkansas, Michigan and Florida — all of which take place before December.

As Biden prolongs his decision, he's also losing momentum and missing opportunities. He was not on stage at the first Democratic debate, which for the first time, showcased the Democratic field to the country. Biden's absence at such events give the declared candidates more exposure and opportunity for voters to solidify their preference.

For instance, after Tuesday's debate, Biden's support suffered slightly, according to an NBC News online poll. In September he garnered support from 15 percent of respondents. After the debate, his support dropped to 10 percent.

In a show of strength, Clinton is compiling a long list of endorsements from Democrats around the country. Those endorsements include two of Biden's current colleagues — members of the Cabinet. Housing and Urban Development Secretary Julian Castro endorsed Clinton Thursday. Agriculture Secretary Tom Vilsack endorsed her previously.

President Barack Obama declined to weigh in on a potential Biden run Friday, saying, "He'll have to figure out if it makes sense for him."

And that's the big question. Biden confidantes maintain that the decision is purely up to Biden and if he is emotionally prepared to do it after the death of his son Beau to brain cancer earlier this year.

Kaufman reiterated that sentiment in his memo to Biden's supporters: "All of you know well that the first and foremost consideration will be the welfare and support of his family. That's Joe Biden. He has been clear about this and it is as true today as it has been for the past several months. He is determined to take, and to give his family, as much time as possible to work this through."

As for the timing, Kaufman said, "I can't add much, except I am confident that the vice president is aware of the practical demands of making a final decision soon."

A decision is expected as early as this weekend.