"All things being equal, like in the beginning of this whole thing when there is uncertainty, people flock to certainty, or less uncertainty and the dollar is the beneficiary," said Thomas Anderson, managing director, at moneycorp in Boston.
The US currency held its gains after data showed US weekly jobless claims totaled a seasonally adjusted 3.169 million for the week ended May 2, down from a revised 3.846 million in the prior week. Economists polled by Reuters had forecast 3.0 million claims in the last week.
In morning trading, the dollar index rose 0.1% to 100.30, just off a two-week high touched earlier in the session of 100.33.
The dollar also gained 0.5% against the yen to 106.60 yen, and climbed 0.3% versus the Swiss franc to 0.9776 franc.
The euro, meanwhile, fell 0.3% against the dollar to $1.0775, earlier dropping to a two-week low of $1.0773, its lowest in two weeks. It has shed more than 1.5% this week and is set for its biggest weekly drop in just over a month.
Sterling was down 0.5% at $1.2284, after rallying earlier following the Bank of England's decision to leave interest rates unchanged and hold off on more stimulus.
Chinese exports rose 3.5% despite expectations of 15.7% drop, helping to lift the Chinese yuan in the offshore market and the Australian dollar. The yuan was last up 0.3% at 7.1095 per US dollar. The Aussie dollar was last up 0.7% at US$0.6449.