MELBOURNE (Reuters) -U.S. President Donald Trump's adviser on critical minerals is set to meet officials of about 30 critical minerals companies in Sydney on Friday, two sources familiar with the matter said, as the U.S. and Australia step up cooperation to diversify supply.

Joshua Kroon, deputy assistant secretary for critical minerals and metals at the U.S. Department of Commerce’s International Trade Administration, has been travelling in Australia despite the U.S. government shutdown. He was in Perth earlier this week, local media reported.

A U.S. embassy spokesperson in Australia declined to comment.

The meeting in Sydney, which has not been previously reported, comes after the U.S. and Australia last week agreed a wide-ranging critical minerals deal aimed at countering China's dominance in the sector, and as companies jostle to get on Trump's radar ahead of a slew of expected funding opportunities.

Kroon last month met several mining and processing companies as part of an Australian trade delegation to Washington and New York, Reuters reported.

(Reporting by Melanie Burton; Editing by Jamie Freed)