The Pentagon said on Saturday it has questioned Moscow over air strikes against U.S.-backed Syrian opposition forces earlier this week, saying Russian forces failed to heed U.S. warnings to stop the attack.

• June 18, 2016

German Foreign Minister Frank-Walter Steinmeier has criticized NATO's decision to stage military maneuvers in eastern Europe, warning such moves could worsen tensions with Russia.

• June 18, 2016

The Kiev government is outraged by remarks made by United Nations Secretary-General Ban Ki-moon about the crucial role Russia can play in ending conflicts, and no longer believes he has any moral authority, Ukraine's U.N. envoy said on Thursday.

• June 16, 2016

Air strikes hit rebel-held parts of Syria's Aleppo city on Thursday just hours into a 48-hour ceasefire announced by Russia to try to curb weeks of intense fighting as government forces battle for control of the whole city.

• June 16, 2016

U.S. Secretary of State John Kerry on Wednesday accused Syrian President Bashar al-Assad and Russia of selectively enforcing a nationwide "cessation of hostilities" agreement in Syria while a government campaign to retake Aleppo continued unabated.

• June 15, 2016

Russia is violating an internationally-agreed ceasefire in Ukraine "again and again", NATO's chief said on Wednesday, accusing Moscow of continuing to arm separatists in the conflict at the center of East-West tensions.

• June 15, 2016

Britain, Germany and the United States advanced plans on Tuesday to spearhead a new NATO force on Russia's border from next year, and Russian President Vladimir Putin ordered snap checks on combat readiness across his armed forces.

• June 14, 2016

Leaders in the Baltic countries and Poland fear the force NATO plans to deploy on their territory is too small and symbolic to deter an attack by Russia, whose 2014 annexation of Crimea is fresh in the memories of the former Soviet-bloc states.

• June 13, 2016