Washington, Boeing will further assess the size of its workforce amid the COVID-19 pandemic, the American airplane giant's President and CEO Dave Calhoun said.

The market simply won't support higher output levels at this time, and the company needs to adapt accordingly, Xinhua news agency reported citing Calhoun as saying in a letter to employees sent on Wednesday.

Boeing previously announced a net 10 per cent workforce reduction in 2020 through a combination of voluntary layoffs, attrition and involuntary layoffs (ILOs) to align to a smaller market.

According to Calhoun, the first wave of associates affected by ILOs received notification in May, and the company continues to conduct smaller, phased workforce reductions to reach the target.

"Managers are communicating the latest wave of those reductions beginning today," he said.

"Regretfully, the prolonged impact of COVID-19 causing further reductions in our production rates and lower demand for commercial services means we'll have to further assess the size of our workforce," Calhoun noted.

"This is difficult news, and I know it adds uncertainty during an already challenging time. We will try to limit the impact on our people as much as possible going forward."

Boeing on Wednesday reported second-quarter revenue of $11.8 billion, GAAP loss per share of $4.20, and operating cash flow of $5.3 billion, primarily reflecting the impacts of COVID-19 and the global grounding of the 737 MAX fleet.

In Commercial Airplanes Programs, Boeing delivered a total of 20 aircraft in the second quarter of 2020.

The delivery included two 777Fs to China Southern Airlines in May.

The backlog included over 4,500 airplanes valued at $326 billion.