After another year of modest expansion, Japan's export-driven growth may be on shaky ground as uncertainty looms over its trading partners, bolstering the case for measures to improve sluggish demand at home.

U.S. President Donald Trump's protectionist stance on trade and his allegations of currency manipulation are expected to remain sources of concern for policymakers, although friction was absent when Trump and Prime Minister Shinzo Abe met this last weekend.

The Japanese economy grew for a fourth quarter in 2016, posting an annualized real 1.0 percent expansion aided by strong exports mainly to the United States and China — the country's two biggest trading partners.