Two of the world's biggest renewables players on Wednesday warned of challenges for the U.S. offshore wind sector under a presidency led by Donald Trump, flagging potential delays for the technology slammed by the president-elect.

Renewable energy companies, including Germany’s RWE and Siemens Energy, have expressed concerns about the future of the US offshore wind sector under President Donald Trump. Both companies anticipate potential delays and regulatory challenges, according to a Reuters news report.

The power utility said risks to offshore wind projects increased following the U.S. election as it warned of delays to its plans off the East Coast due to outstanding permits.

RWE, Germany's biggest utility, said on Tuesday it would buy back up to 1.5 billion euros ($1.6 billion) of shares, citing weakening prospects for hydrogen in Europe and offshore wind in the U.S. in the wake of Donald Trump's election victory.