Why did China's Xi Jinping hold back-to-back calls with Russia's Vladimir Putin & US' Donald Trump?

Chinese President Xi Jinping engaged in rare, back-to-back calls with Russia's Putin and US President Trump, signaling Beijing's global positioning. Discussions covered trade, Ukraine, and Iran, with China committing to increased US soybean purchases. Xi also cautioned the US on arms sales to Taiwan, while strengthening ties with Russia against the West.