Hillary Clinton boards her campaign plane at the Westchester County Airport in White Plains, N.Y., on Nov. 1. (JEWEL SAMAD/AFP via Getty Images)

Hillary Clinton’s campaign will begin airing its first television ads of the general election in Michigan and New Mexico and will return to the airwaves in Virginia and Colorado after a months-long hiatus.

The campaign will air new ads in Albuquerque and statewide in Michigan. In Colorado, the ads will run in the Denver, Grand Junction and Colorado Springs markets. And in Virginia, they will go up in the Richmond, Charlottesville and Roanoke markets. Each of the four states will see a six-figure investment, according to a campaign official.

The news comes at a time when national polls show the presidential race tightening and the Clinton campaign is seeking to shore up support in several states where she had maintained comfortable margins so far. The Democratic presidential nominee began airing new ads in Wisconsin last week — the first ads in that state in the general election.

“The Trump campaign claims their path to White House is through states like these, but we’re going to make sure those doors remain shut,” said Jesse Ferguson, Clinton’s deputy national press secretary. “Fueled by record-breaking fundraising in the last 72 two hours, we are supercharging our GOTV [get out the vote] program with these ads to make sure voters know the urgency and the stakes of voting on November 8th.”

The campaign will air two previously released ads in all four states: "Just One," which characterizes Trump as unfit to serve as "commander-in-chief" and "Role Models," which paints Trump as a bad role model for children.

The Clinton campaign is sitting on a massive war chest —$153 million cash-on-hand combined with the Democratic National Committees and joint state committees at the end of the last Federal Election Commission reporting period.

And in the past 72 hours, the campaign raised a record-breaking $11.3 million online alone, according to a campaign official. During that period, the campaign pushed it's supporters for more money in the wake of news that the FBI had renewed its investigation into Clinton's use of email as secretary of state.

Republican nominee Donald Trump’s campaign also announced Tuesday that it would expand its ad reservations in a number of states, including Michigan, as part of an effort to expand its reach into a group of blue states that have not voted for a Republican in decades. Trump’s campaign believes that a combination of demographics and the resonance of the businessman’s economic message with working-class voters will allow him to perform better there than previous Republicans.

In a statement, Trump's senior communications advisor Jason Miller characterized the Clinton's new ad reservations as a defensive move.

"It’s notable that in the final week of this campaign it is actually the Clinton campaign being put on defense and being forced to start advertising in so-called 'blue states' to hold off Mr. Trump’s surge in the polls, including two states the Clinton campaign boasted of having put away months ago," Miller said. "Not only is Mr. Trump well-positioned to win key Battleground swing states like Florida, North Carolina and Ohio, but he is also well-positioned to win a number of states carried twice by President Obama as part of his effort to become a President for all Americans."

Clinton leads Trump by an average of four points in Colorado, five points in Virginia, seven points in New Mexico, and seven points in Michigan according to Real Clear Politics.