Updated Sales of Microsoft’s Windows RT-based Surface tablet are off to a “modest” start according to chief executive Steve Ballmer.

Ballmer is reported to have given the update to French news site Le Parisien.

Microsoft’s chief executive also used the occasion to boost January’s release of the Intel-based tablets.

Ballmer described the Intel Surface as “high-end” and unique, with a higher-resolution screen.

The Intel-powered device will feature a 1920x1080 10.6-inch screen versus 1366x768 for the RT, up to 128GB storage, and a better battery. The Intel machine will also be fatter and heavier – 13.5mm compared to 9.30 mm – and 2lb as against 1.5. The Intel machines will run Windows 8 Pro and be capable of running existing Windows 7 apps. You can see the spec comparison here.

Microsoft has been hit by shortages of Surface since its launch on October 26. Devices are only available at a selected number of Microsoft Stores internationally and at retail outlets; the company has run out of the cheapest 32-GB units in the US and the UK at times, although they are back in stock again.

It’s early days for Surface but launching in the current trading quarter is important: traditionally, the fourth quarter has been a strong period of sales for PC, phones and games with retailers cashing in on Christmas holiday shopping. Microsoft, meanwhile, likes to boast about new product launches once they’ve hit their first million milestone – whether that’s units shipped or licenses of new versions of Windows sold.

Given the general dropping sales in the PC business coupled with Microsoft’s relatively small inventory of Surface machines, it’ll be interesting to see how soon Surface can hit Microsoft’s million milestone. ®

Update

Microsoft has released an official statement on Ballmer's comments:

“When asked about Surface, Steve’s use of the term 'modest' was in relation to the company’s approach in ramping up supply and distribution of Surface with Windows RT, which has only been available via our online store and Microsoft retail and holiday stores in the U.S. and Canada. While our approach has been modest, Steve notes the reception to the device has been 'fantastic' which is why he also stated that 'soon, it will be available in more countries and in more stores,'" the company said.