The U.S. administration is to punish Russia with sanctions over the Kremlin's alleged involvement in the poisoning of former Russian spy Sergei Skripal in Salisbury, England. According to State Department spokeswoman Heather Nauert, the sanctions will go into effect on or around August 22.
Meanwhile, China on Wednesday imposed additional tariffs of 25 percent on $16 billion worth of U.S. fuel and steel imports, in retaliation to planned extra duties from the U.S. on Chinese products set to be enforced from August 23.
Looking at individual stocks, Adidas topped the European benchmark on Thursday. Shares in the sportswear company pushed higher throughout the day to trade 9.6 percent to the upside following its latest earnings release. The firm showed stronger-than-anticipated second-quarter net profit, despite taking an impairment charge on its struggling Reebok brand.
Pandora shares were trading 1 percent higher mid-afternoon, paring back gains from earlier on in the day made after the firm's chief executive announced that he was leaving his position. The Danish jewelry company issued a profit warning on Wednesday.
At the other end of the index, G4S foundered 7.2 percent after reporting a fall in its first-half profit. The world's largest security group saw its latest figures take a hit from restructuring costs and weaker Middle East revenues.
Shares of Tui sank 4 percent despite the travel company saying that it was on track to deliver a 10 percent rise in profit this year, sticking to its guidance.