Biotech stocks took a hit after Democratic presidential frontrunner Hillary Clinton pledged to take action against runaway price increases on specialty drugs.
The Republican contender Ben Carson ignited a storm of controversy at the weekend, by stating that he saw Islam as incompatible with the charge of head of state.
Greek Prime Minister Alexis Tsipras, who returned to power after Sunday's election, called for "shared" European responsibility in tackling the migrant crisis facing the bloc.
Afghan President Ashraf Ghani condemned last week's deadly attack on a Pakistani air force base and said Afghanistan will never allow its land to be used against Pakistan.
Four eastern EU states opposed to fixed migrant quotas across the bloc said they were "absolutely dedicated" to reaching an agreement with western partners on solving Europe's worst migrant crisis.
The EU congratulated Alexis Tsipras on his left-wing party's re-election victory and said Greece has "no time to lose" in implementing the reforms agreed as part of its international bailout.
Japanese public support for Prime Minister Shinzo Abe has dropped in the days since his ruling coalition rammed through legislation allowing the nation's troops to fight abroad.
Republican presidential hopeful Ben Carson said no Muslim should be president of the United States, adding a new twist to a controversy roiling the party's White House nominating race.
Hundreds of pro-Kiev activists from Crimea's Tatar community launched a blockade of roads from Ukraine to the Crimean peninsula to protest Russia's seizure of their home region.