China is expected to press for assurances on US public deficit and the weakened dollar as a high-profile delegation meets representatives of the Obama administration in Washington today (July 27th), Morgan Stanley has claimed.Speaking to Bloomberg, Wang Qing, an economist at the Hong Kong arm of the global investment group, commented: "If the key issue in the past was the renminbi's exchange rate, now it's the US dollar. What China cares about the most is the stability of the dollar and the stability of US policy."The supremacy of the dollar also came under pressure as Chinese officials questioned its continued legitimacy as the world's reserve currency ahead of the G20 meetings in Italy earlier this month.Ahead of the Washington meeting, Treasury secretary Timothy Geithner has refused to reiterate a written statement submitted to the senate in which he claimed that China was manipulating the yuan, the principal unit of the renminbi.