CEO Travis Kalanick has sent a letter to investors saying that the company is planning to invest more than $1 billion in its Chinese business this year, according to The Wall Street Journal.

It makes sense that China would be an important area for Uber. Earlier this week it was reported that around 10% of all Uber rides take place in China. And Uber is facing serious competition in the country from local player Didi Kuaidi Joint Co, which currently dominates the e-hail market.

But Uber faces challenges in the world’s second largest economy. It has faced raids on its offices, and a crackdown on drivers who were thought to be operating illegally.

The CEO’s note also said that Uber is looking to raise even more money to pour into its China effort, which the Journal notes could be part of an effort to raise $2 billion — funding that would push Uber toward a valuation above $50 billion.