The Dow Jones industrial average was up 23 points, or 0.2 per cent, to 14,833 shortly before noon Eastern Daylight Time Tuesday.
The Standard & Poor's 500 index rose eight points, or 0.5 per cent, to 1,641. The Nasdaq composite rose 27 points, or 0.8 per cent, to 3,617.
Many expected Obama to order strikes immediately and independently of Congress, but on Saturday he said that he would put a vote before lawmakers when they return from summer recess.
Microsoft fell $2.04, or 6 per cent, to $31.36 after the company said it would buy Nokia's smartphone business and a portfolio of patents.