South Korea's Samsung and LG unveiled new smartwatches Thursday with upgraded functions and design as they step up their drive to lead an increasingly competitive market for wearable devices.
The "Gear S" is Samsung's first smartwatch able to make stand-alone phonecalls with built-in 3G alongside Bluetooth and WiFi connectivity.
Users can make and receive calls directly from their wrist, or get calls forwarded from their smartphones. Notifications from  social networks, calendars and applications can also be received.
"It will let consumers live a truly connected life anywhere, anytime," said JK Shin, head of Samsung's IT and mobile communications division.
Global handset and software makers have struggled to diversify from the saturated smartphone sector to wearable devices.
Global smartwatch sales are expected to grow this year by more than 500 percent from 1.9 million units in 2013, according to the market researcher Strategic Analytics.
LG's "G Watch R" features a traditional wristwatch design with a 1.3-inch circular plastic OLED display that the company said provided "stunning image clarity even under bright sunlight".
It runs for up to 30 minutes in one metre of water and is able to receive notifications of missed calls and messages, upcoming events, and weather forecasts.
"We wanted to complement the modern design of the original G Watch with the classic look of the G Watch R," Park Jong-Seok, president of LG's mobile communications unit, said in a statement.
Prices will be disclosed when LG's new device hits key markets early in the fourth quarter.
The world's top smartphone maker Samsung said its Gear S, which features a curved 2-inch "Super AMOLED" display, would be available in global markets from October.
Samsung introduced its Android-based Galaxy Gear smartwatch last year but it was given a lukewarm reception by consumers.
In June, Samsung and LG launched smartwatches powered by Google's new software.