UNITED NATIONS (Reuters) - The United States on Wednesday said it had conducted air strikes on Islamic State targets in Syria within the last hour or so, brushing aside a Russian request to avoid Syrian airspace.

U.S. Secretary of State told the U.N. Security Council that the United States would continue its own air operations and that it would welcome Russian strikes if they were genuinely aimed at the militant group or others affiliated with al Qaeda.

However, he said the United States would be troubled if Russia went after targets where those groups were not present, saying this would raise questions about whether Moscow's main aim was in fact to prop up Syrian President Bashar al-Assad.

"If Russia’s recent actions, and those now ongoing, reflect a genuine commitment to defeat that organization, then we are prepared to welcome those efforts and to find a way to deconflict our operations and thereby multiply the military pressure on ISIL and affiliated groups," Kerry said, saying that such talks could occur as soon as this week.

"The United States and the coalition will continue our ongoing air operations," he added. "We have conducted a number of strikes against ISIL targets in Syria over the past 24 hours, including just an hour ago, and these strikes will continue."

At least 200,000 people have been killed and millions driven from their homes since the Syrian civil war began more than four years ago when Assad's forces moved to crush peaceful protests against his family's four-decade rule.

"We must not and will not be confused in our fight against ISIL with support for Assad," Kerry said. "ISIL itself cannot be defeated as long as Bashar al-Assad remains president of Syria."

(Reporting by Michelle Nichols and Arshad Mohammed; Editing by David Storey and Christian Plumb)