T-Mobile USA is trying to top Verizon's latest move by adding high-definition video and 10GB of high-speed hotspot usage to its $70 unlimited smartphone data plan.

T-Mobile CEO John Legere made the announcement on Twitter today, saying that the T-Mobile One plan will get HD video and the 10GB of high-speed hotspot data per month beginning Friday "at no extra charge." The T-Mobile One plan costs $70 a month, including taxes and fees. Currently, the $70 plan limits streaming video quality to 480p and caps mobile hotspot speeds at 512kbps, though customers could already pay extra for HD video and high-speed tethering.

6/ Starting Fri, #TMobileONE price includes HD video & 10GB high-speed 📱hotspot data –all at no extra charge. AND taxes & fees are included! — John Legere (@JohnLegere) February 13, 2017

T-Mobile's move comes in response to Verizon Wireless offering an $80-per-month unlimited data plan with 10GB of high-speed hotspot data and no limitations on video. Verizon had stopped offering unlimited data to new customers in 2011.

So far, T-Mobile's implementation of HD video on T-Mobile One has been cumbersome because it isn't automatically enabled even if you pay extra for it. Currently, the T-Mobile "One Plus" plan that costs $85 a month includes "unlimited HD day passes," but customers have to switch HD video on every day that they want higher-definition video. (T-Mobile's current pricing also includes a $95-per-month plan that comes with the HD day passes and unlimited high-speed tethering.)

It would be nice if T-Mobile just enabled HD video at all times if you're paying for a plan that allows it. We've asked the company if it plans to change that Friday and will provide an update if we get one.

Legere also said T-Mobile will offer a promotional price of $100 a month for two lines. Currently, T-Mobile charges $120 for two lines, $140 for three lines, and $160 for four lines.

UPDATE: T-Mobile responded to our question about HD video day passes by saying, "All customers have to do to get HD is go into the app or online to turn on. It’s very easy." Customers still have to enable HD video every 24 hours or it reverts to 480p, a T-Mobile spokesperson told Ars via e-mail. However, the company's Twitter support account says it only will have to be enabled once per month. T-Mobile's press release doesn't clear things up.

UPDATE 2: The T-Mobile spokesperson now says that HD video will only have to be enabled once every 30 days, so that confusion seems to be cleared up. The era of T-Mobile's "HD day passes" appears to be over.

Separately, T-Mobile told us there will be no changes to the One Plus plans that cost $85 and $95. "Those plans include a lot more features than just HD and tethering, so some customers may still choose that option," T-Mobile said.

As for what resolution HD video will be displayed in, T-Mobile told Ars that "HD video will be displayed in whatever resolution provided by the content provider."