Alphabet’s Google has advised some employees on US visas to avoid international travel due to delays at embassies, Business Insider reported on Friday, citing an internal email.

The email, sent by the company’s outside counsel BAL Immigration Law on Thursday, warned staff who need a visa stamp to re-enter the United States not to leave the country because visa processing times have lengthened, the report said.

Google did not immediately respond to a Reuters request for comment.

Some US embassies and consulates face visa appointment delays of up to 12 months, the memo said, warning that international travel will “risk an extended stay outside the US”, according to the report.

The administration of US President Donald Trump this month announced increased vetting of applicants for H-1B visas for highly skilled workers, including screening social media accounts.

The H-1B visa programme, widely used by the US technology sector to hire skilled workers from India and China, has been under the spotlight after the Trump administration imposed a $100,000 fee for new applications this year.

In September, Google’s parent company Alphabet had strongly advised its employees to avoid international travel and urged H-1B visa holders to remain in the US, according to an email seen by Reuters.