AMMAN (Reuters) - The Syrian opposition will demand "qualitative military support" at talks with major powers in Rome this week to help in its struggle to oust President Bashar al-Assad, a leading Assad opponent said on Wednesday.

The announcement during an interview with Reuters came after the United States said it would increase aid to the opposition in an effort to speed a political transition in Syria, now torn by civil war.

"We ask our friends to give us every backing to achieve gains on the ground and help reach a political solution from a position of strength, not weakness," Riad Seif of the Syrian National Coalition umbrella group said a day before a Friends of Syria conference in the Italian capital.

"We expect to receive political, humanitarian and qualitative military support," he said. The Friends of Syria group is comprised mainly of Western powers, Gulf Arab states opposed to the Iranian-backed Assad, and Turkey.

Seif, founder of the Western- and Arab-backed coalition who serves as one of its two vice-presidents, declined to be drawn into details but said there would be "special meetings" to discuss the military support issue.

The Washington Post has reported that the White House is considering a shift in policy toward the nearly two-year-long conflict in Syria and may send the rebels body armor and armed vehicles, and possibly provide military training. U.S. officials still oppose providing arms, the Post said.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Mark Heinrich)