The phone will be available in November for $299. Motorola will begin preorders Oct. 27.
Motorola said it will be the thinnest smartphone available and has other new features such as water resistance and a Kevlar case. It will run on Google's Android mobile software and boasts as much as 30 percent more battery life than competitive devices, Motorola CEO Sanjay Jha said at an event in New York.
The phone will run on Verizon Wireless's faster fourth-generation network.
Jha also showed a wearable device called MotoActv that monitors music preferences and fitness statistics. It is also enabled for global-positioning systems.
Motorola, which this year announced it will be taken over by Google for $12.5 billion, is fighting to retain market share. Its piece of the US market fell to 14 percent by the end of August, from 15.1 percent as of the end of May, according to researcher comScore. Motorola trails Samsung Electronics Co. Ltd. and LG Corp.