BRUSSELS - European stocks extended their decline on Monday, with all major benchmark indexes plummeting as concerns over the escalating trade standoff sparked by US tariffs intensified.

All leading European indexes opened in the red, dropping by 4-7 percent compared to the previous trading day's close.

Britain's blue-chip FTSE 100 index fell by about 5 percent, while Germany's DAX opened 9 percent lower. France's CAC 40 dropped by more than 5 percent, and the pan-European STOXX 600 index fell over 6 percent in morning trading at the time of this report.

Monday's sharp drop is a continuation of the ongoing losing streak in European stock markets, which has persisted for over a week. The STOXX 600 index saw a loss of more than 8 percent last week.

The DAX index was one of the hardest hit on Monday, opening down by 9.5 percent before paring back part of the losses later in the morning. In mid-March, DAX reached a new record high of 23,476 points. It is now down as much as 21 percent from that record high.

According to German media outlet Handelsblatt, it has entered a bear market as this occurs when an index loses at least 20 percent from a record or all-time high.

Earlier this month, US President Donald Trump unveiled sweeping import tariffs and slapped "reciprocal tariffs" on a spate of countries, triggering stock market turmoil worldwide.