"Without good intelligence, sending large numbers of troops across the border or dropping bombs doesn't seem to make much sense to me," he told reporters after talks with NATO defence ministers in the Netherlands.

This applied "for anybody" considering such action, he added.

Turkish warplanes reportedly bombed Kurdistan Workers' Party (PKK) targets along the Iraqi border Wednesday, as the country's leaders met to consider what other measures to take against the Kurdish rebels in northern Iraq.

On Sunday, Gates urged Ankara to show restraint, saying that it was essential to collect intelligence for find those responsible before launching any attacks.

A White House spokeswoman said Tuesday that the United States might provide Turkey with information to enable its armed forces to strike Kurdish rebels using Iraq as a rear base.

"Actionable intelligence is something that we can provide," she said.