European stocks declined for the first session in six days away from four-week highs on active profit-taking, while investors shun risks.
Western countries, led by the US, are preparing more sanctions on Russia amid the intensifying humanitarian crisis in Ukrainian cities.
Dow Jones Stoxx Europe 600 fell 0.7% as of 11:50 GMT, after marking February 23 highs, while closing yesterday up 0.85%.
The Stoxx Europe index declined today for the first session in six away from four-week highs, with most sectors declining, led by the banking sector, which fell 1.1%.
US President Joe Biden is heading to Brussels on Wednesday to attend an emergency NATO summit while speaking to European leaders at the European Council.
In Europe, the euro stoxx 50 fell 0.8%, while France's CAC 40 declined 0.7%, as Germany's DAX shed 1%, while London's Financial Times lost 0.2%.
S&P 500 futures fell 0.5% today, after closing up 1.1% yesterday, marking month highs at 4,522.