Michael Bloomberg will spend tens of millions of dollars on television ads, which would set a record, in at least 100 media markets across the country starting next week, a sign that he could announce his presidential campaign in the coming days.

The ads, some of which are 60 seconds long, are expected to air from Nov. 25 through Dec. 3. They are expected to cost Bloomberg at least $30 million, the New York Times and ABC reported. The sum is more than half of the about $50 million all the other Democratic presidential candidates combined have spent on television ads this year, according to FiveThirtyEight.

Ad spending tracking group Advertising Analyics said that the ad buy would be the largest-ever sum spent in one week by a candidate. President Barack Obama holds the current record of $24.9 million spent during the last week of his presidential campaign.

The former New York mayor has filed to appear on Democratic primary ballots in some states and, on Thursday, filed statement of candidacy paperwork with the Federal Election Commission. But his team indicated that the steps were formalities while he decides whether to launch a presidential campaign, and he has yet to announce a bid personally.

Bloomberg, who is worth an estimated $54 billion, is expected to self-finance his campaign and skip competing in the first four early nominating contest states: Iowa, New Hampshire, Nevada, and South Carolina. Instead, he will focus on winning delegates from primaries on the March 3 "Super Tuesday" and beyond.

Tom Steyer, a former hedge-fund manager worth about $1.6 billion who is also largely self-financing his campaign, is the only other presidential candidate to spend unusually large sums of money on television ads so far in the 2020 cycle. He has spent about $39 million so far on television ads.

Other Democratic presidential candidates have criticized Bloomberg's expected late entry into the large field of candidates and accused him of trying to buy the election.