The launch of the phones, the Nexus 6P and the Nexus 5X, comes a day after Apple Inc reported record first-weekend sales of its new iPhones.
The Nexus 5X 16 GB model will be priced at $379, while the Nexus 6P 32 GB will cost $499, Google said at an event live-streamed on YouTube.
Google also unveiled its first tablet based on the Android operating system.
The latest version of Android, dubbed Marshmallow, will roll out to existing Nexus customers from next week. Features include Doze, which puts a phone into sleep mode when it's not being used, helping to save battery life.
The Android mobile platform is a key element in Google's strategy to maintain revenue from online advertising as people switch from Web browser searches to smartphone apps.
The Nexus 5X is made by South Korea's LG Electronics Inc and the Nexus 6P by China's Huawei Technologies Co Ltd. Both phones feature Google's new fingerprint sensor, Nexus Imprint, which is located on the back.
The fingerprint sensors will help quickly authorize purchases made through Android Pay, the one-touch payment app on Android devices.
Android Pay will compete with Apple Pay in the mobile payments market, which research firm IDC estimates to be worth $1 trillion by 2017.
The phones are available for pre-order on the Google Store from a number of countries including the United States, the United Kingdom, Ireland and Japan.
The Pixel C tablet will cost $499 for the 32 GB model and can be bought with a detachable keyboard, which will cost $149.
The tablet will be available in time for the holiday shopping season on the Google Store.
The Pixel tablet puts Google squarely in the sights of its biggest competitors, Apple's iPad Pro and Microsoft Corp's Surface tablets, which also have optional keyboards.
Google also unveiled a redesigned version of its Chromecast device for streaming Web content to TVs and introduced Chromecast Audio, which plugs into speakers to stream audio over Wi-Fi. Chromecast Audio, priced at $35, works with apps including Spotify, Pandora and Google Play Music. — Reuters
