China’s economic growth slowed by more than expected in the second quarter, official statistics showed Monday.

The economy grew at a 6.2 percent annual rate in the April through June period, the slowest quarterly expansion in decades. U.S. tariffs and uncertainty around trade negotiations weighed on growth. Economists had expected to economy to0 slow to a 6.3 percent annualized pace after growing at a 6.4 percent rate in the first three months of the year.

The trade fight appears to have held back investment despite government encouragement and big tax breaks aimed at stimulating the economy. Exports fell on a year-over-year basis in June as higher U.S. tariffs kicked in.

The second quarter was the slowest pace of economic growth since the government began publishing official statistics in 1992.

President Donald Trump tweeted about the sluggishness of China’s economy on Monday.