The U.S. dollar rose against most major currencies this week against the backdrop of the ongoing European debt crisis and upbeat economic data.
The auction of Italian five-year government bonds on Monday produced a yield of 6.29 percent, a sharp rise from the 5.32 percent last month.
Also, some analysts noted that Spain's 10-year note yields topped 6 percent for the first time since early August, suggesting the borrowing costs of Spain also rose due to concerns over the country's debt problems.
The Spanish government on Thursday sold 3.56 billion euros (4.8 billion U.S. dollars) worth of 10-year bonds at an average yield of nearly 7 percent, which is a level seen as unsustainable.
The rising yields of government bonds worried investors as the European debt crisis seemed to be spreading in eurozone countries.
The European Union, the European Central Bank, and the International Monetary Fund have approved an 8-billion-euro (10.8-billion-dollar) installment for Portugal's bailout package, while Greek Prime Minister Lucas Papademos won a confidence vote which was crucial to implementing austerity measures.
On the economic front, eurozone gross domestic product (GDP) expanded by 0.2 percent in the third quarter, led by Germany and France. The GDP data eased investors' worries about an economic recession in the region.
However, European Commission President Jose Manuel Barroso on Wednesday said the eurozone faces a "systemic crisis" that calls for more action by euro-member states.
Meanwhile, U.S. economic data this week showed that the U.S. economy might pick up momentum. The U.S. Labor Department said on Wednesday that consumer prices dropped 0.1 percent during the month, the first decline in four months, as energy prices decreased.
The Labor Department also said initial claims for unemployment compensation fell by 5,000 to a seasonally adjusted 388,000 last week, which was the lowest level in seven months, suggesting that the U.S. labor market continued to improve.
The dollar index, which is regarded as the best gauge of its performance against a basket of six currencies, rallied 1.5 percent to 78.079 this week.
The British pound dropped 1.74 percent against the dollar this week. Britain's Office for National Statistics said consumer prices fell to 5 percent in October from 5.2 percent in September. However, the figure was still well above the 2 percent target set by Bank of England.