WASHINGTON - Some of the 1,500 U.S. troops authorized to advise and train Iraqi forces in their fight against Islamic State militants will deploy to the country in the next few weeks without waiting for Congress to fund the mission, the Pentagon said on Thursday.

WASHINGTON � Some of the 1,500 U.S. troops authorized to advise and train Iraqi forces in their fight against Islamic State militants will deploy to the country in the next few weeks without waiting for Congress to fund the mission, the Pentagon said on Thursday.

Rear Adm. John Kirby, the Pentagon press secretary, said leading elements of the U.S. force would begin moving to Iraq in the coming weeks, even if Congress has not yet acted on a $5.6 billion supplemental request to fund the expanded fight against the militants who overran northwestern Iraq this year.

Officials initially indicated that they needed lawmakers to approve the funding before the Pentagon could start the mission, but Gen. Lloyd Austin, the head of U.S. troops in the Middle East, recommended starting by using available resources.

Kirby�s comments came just days after U.S. officials said about 50 special-operations troops had been sent to Ain al-Asad air base in Anbar province in Iraq to advise and train Iraqi troops.

The Obama administration announced on Nov. 7 plans to roughly double the number of U.S. troops in Iraq, adding 1,500 to establish sites to train nine Iraqi military brigades and three Kurdish peshmerga brigades.

Kirby indicated that additional U.S. troops would begin deploying to Iraq before 2015.

�You�re going to start to see initial elements of the 1,500 or so additional start to flow in the next few weeks,� he said. �By the end of the calendar year, you�re going to see a much more robust presence, not just by the United States doing this but by coalition partners as well.�