"Our industry has entered a new era of ethical responsibility: the choices we make matter on a global scale", the letter states, specifically referencing the Chinese search engine project, codenamed Dragonfly.
But according to the reports last month, the company is working in a secret way on a new search service for China known as "Dragonfly" internally.
But the search engine giant's growing capabilities has it feeling lucky too.
Ms Wong called on tech firms looking to do business in China to have plans in place to improve the censorship and the human rights situation, which she said has worsened since Google pulled out.
Pichai's remarks, shared with CNBC by a Google employee, come in the of wake of internal and external backlash following a report from The Intercept in early August that the company was secretly building a censored version of its search engine to launch in China.
The company had also stated that Chinese hackers had tried to hack its servers and steal information from Gmail accounts of human rights activists. Google wants to provide multiple subtopic options in order to better guess what the searcher wants to know and show you multiple aspects of a topic with a single search.
The employees were not given details about the project and they are now angry after a report leaked about Google working on such a project.
The employees are demanding more transparency so they can understand the moral implications of their work, said the New York Times, which obtained a copy of the letter.
China restricts internet users by blocking websites, censoring words and clamping down on free speech.
"Currently we do not have the information required to make ethically-informed decisions about our work, our projects, and our employment", they say in the letter, according to the Times.
Rumors of the Chinese-based search engine have circulated over the past few weeks after The Intercept reported that it had seen leaked documents, suggesting the Sundar Pichai-led Google was planning to re-enter China, almost 8 years after leaving the country.
Before the staff meeting, employees called for more "transparency, oversight and accountability" - according to an internal petition. At the meeting, Pichai reportedly said that the company "has been in an exploration stage for quite a while now".
China is one-fifth of the world's population. "I think if we were to do our mission well, I think we have to think seriously about how we do more in China", Mr Pichai said.
"We'll definitely be transparent as we get closer to actually having a plan of record here".
The tech titan faced similar employee uproar earlier this year over "Project Maven", a pilot program that planned to use technology to assist Department of Defense surveillance operations.