The World Bank has warned of grave consequences for the global economy, if politicians in the United States failed to increase the government's borrowing limit. US officials have said that the treasury will start or run short of funds on Thursday, unless Congress allows it to borrow more in the financial markets. The Republicans have sought concessions from President Obama and there have been some signs of movement, in the last few days. But there is no deal , and the World Bank President Jim Yong Kim called on them to agree and to do so quickly. The concern is that, if the US ran short of cash, it might default on its debts in the financial markets. That would cause a shock to reverberate throughout the international financial market system.