The on Google's website since the middle of this week after running out of stock, and was still not available for order on the Google Play store as of Friday. Availability of the tablet is becoming even tougher as retailers like Staples and Office Depot have stopped taking online orders, while GameStop and Adorama have delayed the shipping dates for the tablet to the middle or end of August.

The 16GB Nexus 7 tablet will come back "soon" on Google's Play store, said a Google spokeswoman in an e-mail on Friday.

"We haven't shared a timeline," she said. An 8GB version of the Nexus 7 tablet for $199 in the Google Play store.

The 16GB tablet, which is priced at US$249, started shipping on July 13, but issues mounted almost immediately with retailers like Staples, GameStop and Adorama shipping commitments after receiving limited stocks of tablets.

Staples has now stopped taking orders for the 16GB tablet, putting it on "special order" and . Staples earlier delayed shipments by a few days after the tablet started shipping, but was still taking orders. Staples has also put the 8GB Nexus 7 on special order.