Pfizer CEO Ian Read has confirmed his company's commitment to the planned AstraZeneca Cambridge campus in order to ease fears of the pharmaceutical research and development industry in the UK.

The US drugmaker proposed a £63bn merger with UK rival AstraZeneca, which is yet to accept the offer.

In a video uploaded on its website, Read noted that research and development (R&D) is key to its business, saying "without a great innovative core, you don't have a pharmaceutical company".

Read cited the example of Wyeth, which was acquired by Pfizer in 2009. As part of the transaction, Pfizer brought in "a lot of talent" from Wyeth, according to Read.

In the US, the company has hubs of science in La Jolla and in the Bay Area and in Cambridge, Massachusetts, and it is working with 23 universities in the country to co-fund "exciting" innovations.

"We've taken our research, which was also disbursed across the US and we've moved a lot of the research to Cambridge, Massachusetts. This is an area where there is a lot of exciting science being done, a lot of universities, a lot of talent where we can combine chemistry and biology, and we are very positive about our investment in Cambridge, Massachusetts," he said.

He noted that there are similarities between Cambridge, Massachusetts, and the UK.

"UK, I see great similarities with Cambridge, Massachusetts where you have this hub of innovation, this hub of young scientists, where you see between Cambridge and Oxford and London huge opportunities in science," he added.

"So the strategy to build a centre in Cambridge in fact is in line with our strategy, as we've shown by what we've done in Massachusetts."

Earlier, Read sent a letter to David Cameron committing the company to complete the construction of the planned AstraZeneca Cambridge campus that would be a substantial R&D innovation hub in the country. The facility will lead all the company's European and certain global R&D functions.

In addition, the company promised that 20% of the combined company's R&D workforce would be based in the UK and the commercial manufacturing facilities at Macclefield would be retained.