New York (CNN Business) America's manufacturing downturn isn't letting up. Factory activity contracted for the fifth consecutive month in December, registering a worse drop than expected.

The Institute of Supply Management's manufacturing purchasing managers' index logged its lowest level since June 2009 at 47.2, compared with the consensus forecast of 49. It stood at 48.1 in November. Any number below 50 denotes a contraction.

"Global trade remains the most significant cross-industry issue, but there are signs that several industry sectors will improve as a result of the 'phase one' trade agreement between the US and China," said Timothy Fiore, chair of the ISM manufacturing business survey committee.

Last week, the Federal Reserve argued in a paper that import tariffs hurt US manufacturing. "A positive effect from import protection is offset by larger negative effects from rising input costs and retaliatory tariffs," it said.

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