The United States will not cooperate militarily with Russia in Syria because Moscow's strategy is "tragically flawed", U.S. Defense Secretary Ash Carter said on Wednesday in his strongest comments yet on the issue.

• October 7, 2015

Syrian state television and a monitoring group said on Tuesday that Russian jets hit Islamic State targets in the Syrian city of Palmyra and the northern province of Aleppo, in some of the heaviest Russian attacks on the hardline Islamist group.

• October 6, 2015

Syrian state television and a monitoring group said on Tuesday that Russian jets hit Islamic State targets in the Syrian city of Palmyra and the northern province of Aleppo, in some of the heaviest Russian attacks on the hardline Islamist group.

• October 6, 2015

U.S. Secretary of State John Kerry said on Monday the United States was "greatly concerned" about the incursion by a Russian plane into Turkish airspace over the weekend and he had intensified discussions with Moscow.

• October 5, 2015

Ukraine has started withdrawing tanks and light artillery from the frontline in the eastern region of Luhansk in line with an agreement with Russian-backed separatists, Kiev's military said on Monday.

• October 5, 2015

Russian jets hit Islamic State targets and other rebel groups in Syria on Saturday, on a fourth day of air strikes by Moscow in support of President Bashar al-Assad which have dramatically escalated foreign intervention in Syria.

• October 3, 2015

Russia said on Saturday it will step up air strikes in Syria, escalating a military intervention which Moscow says is weakening Islamic State militants but which Western powers say aims to support President Bashar al-Assad.

• October 3, 2015

Syrian Foreign Minister Walid al-Moualem on Friday questioned the value of political negotiations and said air strikes against militants in his country are useless if they are not coordinated with his government.

• October 2, 2015