Chinese firm sues Obama

A Chinese-owned firm in the US is suing President Barack Obama after he blocked a wind farm deal on national security grounds.

Ralls Corp, a private firm, acquired four wind farm projects near a US naval facility in Oregon earlier this year.

Obama signed the order blocking the deal last week.

The lawsuit alleges the US government overstepped its authority.

The block on the wind farms comes just weeks ahead of November's US presidential election.

Obama has been criticised by the Republican nominee, Mitt Romney, for not taking a tough enough line with China over trade and investment practices.