The U.S. dollar index is at its highest levels since February, gaining over a point on sheer greenback strength on Friday.

Even after the release of a slightly worse-than-expected preliminary second-quarter nonfarm productivity report at 8:30 a.m. EDT, the U.S. dollar index is up 1.074 points to 75.621. It had a session high of 75.662, 1.090 points above session-open levels.

U.S. unit labour costs rose just less than expected at an annual rate of 1.3% while nonfarm productivity came in lower than expected at an annual rate of 2.2%, according to the U.S. Bureau of Labor Statistics.

"Despite hefty job losses companies were unable to cut staff fast enough to prevent productivity falling. With comp costs up 4.6% in the sector, durable [manufacturing] unit labor costs rose 6.1% q/q," wrote HFE chief U.S. economist Ian Shepherdson. "Whole economy data not too bad at all, nonfarm [unit labour costs] up only 1.5% y/y, but [manufacturing] is in trouble."

The U.S. dollar is up 0.58 to 110.02 against the yen and up 0.0149 to 1.0679 against the Canadian dollar. The USD/CAD increased 0.0056 to 1.068 towards current levels on weak Canadian employment data at 7 a.m. EDT.

The pound sterling is down 0.0244 to 1.9195, while the euro is down 0.0260 to 1.5064, both against the U.S. dollar. While no top-tier data came out of the euro zone overnight, the euro's losses are in part attributable to European Central Bank President Jean-Claude Trichet's comments on Thursday, which were interpreted as dovish.

The Australian dollar is down 0.0154 to 0.8913 against the greenback, suffering a gradual slide down since the open.

"USD has extended yesterday's rally, with a further significant leg higher in Asia and another in London, taking EUR/USD down to a low of 1.5129," wrote RBC Capital Markets global head of FX strategy Adam Cole. "All the majors and most EM currencies are down against USD relative to North America closing levels, though AUD and NZD are the notable underperformers, both losing 1.6% (see below). Overnight news flow was extremely light and price action was dominated by capitulation of USD shorts as key technical levels broke."

USD/JPY up 0.58 to 110.02.

EUR/USD down 0.0260 to 1.5064.

GBP/USD down 0.0244 to 1.9195.

USD/CAD up 0.0149 to 1.0679.

AUD/USD down 0.0154 to 0.8913.

All data taken at 8:49 a.m. EDT.

By Ryan Szporer with contributions from Patrick McGee and edited by Megan Ainscow