Sterling fell against the dollar after a deadline was set for the start of the formal process that will split Britain from the EU.
The euro erased losses against the dollar after hitting a nine-day low on reduced concerns surrounding Deutsche Bank's health.
The U.S. dollar hit an eight-day high against the yen on Thursday on reduced appetite for the safe-haven currency.
The U.S. dollar hit a roughly five-month low after OPEC sources told Reuters the producing group agreed to reduce its oil output.
The dollar rose against the euro after concerns surrounding Deutsche Bank caused general unease over Europe's banking sector.
The dollar fell against the yen after comments from a top BOJ official and uncertainty from impending U.S. presidential debate.
The dollar index edged higher on Friday, reversing earlier selling, after comments from Boston Fed Reserve President Eric Rosengren.
The dollar was mixed after a Fed meeting that balanced hints of a rise in interest rates this year with cuts in the longer term outlook.
The dollar extended losses against a basket of major currencies after the U.S. Federal Reserve left monetary policy unchanged.
The dollar edged up against major currencies on Tuesday in light trading as investors retraced last week's moves ahead of meetings.
The dollar fell with a stronger oil price the chief theme in a market battening down the hatches ahead of Fed and BOJ meetings.
Hong Kong's overnight yuan borrowing rate was fixed at the highest level in eight months on Monday after the long holiday weekend.
The dollar was on course to fall after U.S. retail sales data quelled lingering bets on the Fed raising interest rates next week.
The U.S. dollar reversed earlier gains against the yen on Thursday as traders doubted that the Bank of Japan (BOJ) would be able to weaken the yen.
The U.S. dollar eased against the yen on Wednesday after skepticism grew that the Bank of Japan would intensify its stimulative monetary policies.
The U.S. dollar gained against the yen and riskier commodity currencies such as the Australian and New Zealand dollars on Tuesday.
The dollar fell against the safe-haven yen as uncertainty surrounding a potential Fed rate hike this month fueled a selloff in riskier currencies.
The dollar rose on Friday as remarks by Federal Reserve policymakers helped boost investor expectations of a near-term increase in U.S. interest rates.
The dollar rose against the yen on Thursday, spurred by a jump in oil prices that put upward pressure on U.S. inflation expectations.
The dollar fell against the yen after a report from the Sankei newspaper that Bank of Japan policymakers are divided ahead of the central bank's next meeting.