T-Mobile US CEO John Legere told CNBC on Monday that the carrier's blockbuster buyout of Sprint will "supercharge" competition and wireless speeds.

"Services are going to be broadened, prices are going to go down, speeds are going to go up," Legere said in a "Squawk on the Street" interview alongside Sprint CEO Marcelo Claure. "If you liked the competition before, you're going to love what's coming with this one."

Legere declined to say what consumers can expect their phone bills to look like as a result of the deal but promised to always have the lowest price out of the major carriers.

Shares of Sprint were more than 13 percent lower midmorning Monday, with T-Mobile off 6 percent, on concerns about whether U.S. regulators will approve the deal.

"All roads lead to Washington," Legere said, playing the nationalist card in his case to the Trump administration. China is beating the United States on 5G next-generation wireless but the new company can change that, he said. "We are behind. It's the early innovation cycle of 5G. We are behind China. This is not something we can allow."

He added the GOP's tax cut increased the deal's value.