Japan's benchmark Nikkei stock index saw another sharp decline on Monday over concerns about a slowdown of the U.S. economy and the stronger yen.

The 225-issue Nikkei Stock Average briefly dropped over 2,500 points, or 7 percent, from Friday's close in the morning session at one point, falling below the 34,000 threshold.

This marked its lowest intraday level in about seven months since January, and market watchers noted that the index has plunged by over 20 percent from its peak in July.

Investor sentiment has been dampened after the U.S. employment data in July showed job growth falling short of market expectations, further fueling fears of economic deceleration.

Meanwhile, losses in U.S. tech stocks have added to the downward pressure here in Tokyo, with Tokyo Electron plunging over 10 percent at one point.

In the Tokyo foreign exchange market on the same day, the yen strengthened against the U.S. dollar to its highest level since mid-January, briefly reaching the lower 145 range per dollar.