The comment comes as rumors suggest his subsidiary Sprint is eyeing a possible T-Mobile buyout.
Yahoo Japan, partly owned by SoftBank and Yahoo, plans to use the acquisition to launch its own mobile Internet service.
Masayoshi Son, who'll be pitching US policymakers Tuesday to consider a stronger wireless industry to vie with broadband, might need T-Mobile to achieve his ultimate goals.
SoftBank CEO Masayoshi Son will reportedly argue that having a strong third mobile carrier will help even the playing field for in-home broadband.
The original version of this story mischaracterized the FCC's role in reviewing the proposed Sprint buyout by SoftBank.
The $21.6 billion deal was made complicated by a bidding war between SoftBank and Dish Network.
The FCC unanimously gives the green light to SoftBank's $21.6 billion bid for Sprint Nextel as well as Sprint's purchase of Clearwire.
Japan's SoftBank is a step closer to acquiring the third largest wireless operator in the U.S., as 98 percent of Sprint shareholders OK the merger.
As Dish and SoftBank duke it out to merge with Sprint, SoftBank raises its offer by $1.5 billion.
Two of three commissioners have signed off on Softbank's $21.6 billion deal for the wireless provider, sources tell Bloomberg.