AstraZeneca has warned that Russian sanctions could have an impact on future earnings, but remained tight-lipped over the possibility it may have to field another takeover bid from US drug maker Pfizer.

Speaking on a conference call after reporting first half year results, AstraZeneca CEO Pascal Soriot said the sanctions may impact the company this year but since its products has a retail focus, the damage should be limited.

He would not be drawn over whether the UK drugmaker will have to try and stave off another takeover attempt by Pfizer.

Earlier on 31 July, AstraZeneca beat analyst expectations and posted a 4% rise in revenues, reaching £3.81bn (€4.8bn, $6.45bn). Analysts only expected a 1% rise in revenue.

The group said it more than doubled its sales for diabetes medicines and profits were boosted by the surge in uptakes for its new heart drug Brilinta.

"We have made significant progress in the first half of the year, with visible momentum across our cardiovascular, diabetes and respiratory franchises as well as strong growth in the emerging markets," said Soriot in a statement.

"This has driven revenue growth for the second consecutive quarter and achieved a 13% increase in core earnings per share in the quarter. The pace of execution of our strategy and the underlying performance of our teams give us confidence to raise 2014 guidance for the full year."

In May this year, Pfizer officially withdrew its takeover attempt of AstraZeneca after the group batted away its $69bn bid for the drugmaker.

Soriot told a panel of politicians, who were questioning the drugmaker boss over how a merger would affect British jobs and the economy, that AstraZeneca was able to go it alone as it was financially strong enough to compete with other pharmaceutical behemoths.

Echoing his pledge that AstraZeneca has many other products in the pipeline, Soriot said in the group's results statement on 31 July that "we now have one of the most exciting pipelines in the industry with 14 assets in late stage development."

"Over recent weeks, we have presented compelling data that demonstrate our potential to significantly advance the way patients are treated, including in immuno-oncology. The quality of transformation we are seeing across all core areas of our business further underpins our confidence in AstraZeneca's longer term prospects," he added.