Google on Monday began restricting visits to its offices in Silicon Valley, San Francisco and New York as it ramped up precautions against the deadly novel coronavirus.

The added measure was enacted as word went out that Apple had joined the list of technology firms advising employees to work from home and that the prestigious TED Conference set to take place in April has been delayed to protect the health of attendees.

To reduce novel coronavirus risk, "external/social visits" to some Google offices have been restricted, and all job interviews will be "virtual" instead of face-to-face for the foreseeable future, according to a spokesperson.

Google was already among technology companies including Facebook, Microsoft and Amazon that have given employees the option of working from home instead of going to the office.

Apple over the weekend told employees at most of its offices around the world that they can work from home this week, according to an internal memo reported by Bloomberg and confirmed by Axios.

Twitter staff across the world was asked to work from home starting Monday in an effort to stop the spread of the new coronavirus epidemic. 

Google last week cancelled its major annual gathering of software developers amid virus concerns.

The internet giant said it nixed the festival-like event Google I/O event scheduled for May a short distance from the "Googleplex" in the Silicon Valley city of Mountain View.

The annual Google I/O conference typically attracts thousands of developers from around the world to mingle with one another and with engineers from the internet company on ways to synchronize software and services to its array of offerings.

It joined a growing list of global events that have been cancelled as the virus spreads around the world. 

A game developers conference in San Francisco was postponed, and Facebook recently cancelled its F8 developers conference, the biggest annual event for the US tech giant, due to virus worries.

Like Google I/O, the F8 gathering in the Silicon Valley city of San Jose typically draws throngs of software makers from around the world who collaborate with the tech giant on its platform.

Face-to-face interaction at the San Jose conference center will be replaced with online presentations.

A TED conference slated to take place in Vancouver next month was postponed until late July after a majority of attendees voted to delay the real-world gathering instead of replacing it with streamed presentations, organizers said on Monday.

The annual gathering, renowned for exploring "ideas worth spreading," typically attracts the brilliant, influential and accomplished and is a stage for the popular "TED Talks" made available free online.

The major annual South By Southwest cultural conference slated to take place in Austin, Texas, was also cancelled due to coronavirus concerns.