The Australian government announced in October it was sending special forces to Iraq to help fight Islamic State extremists and Australian war planes have led international air strikes, destroying key IS targets.
On Saturday President Obama approved sending up to 1500 additional troops to aid the Baghdad government and Kurdish forces fighting IS, also known as ISIL, roughly doubling the number of US troops in the country.
Speaking to reporters in Melbourne, Mr Abbott welcomed the US announcement but said what the US did was a matter for the US.
"Obviously we work in very close partnership with the United States, with the United Kingdom, with a number of other countries," he told reporters.
"This is a very broad coalition, it's not just the United States.
"Our commitment is clear, it's up to eight Super Hornet strike aircraft ... it's up to 200 special forces.
"We have made a strong commitment to disrupting and degrading the ISIL death cult and we continue to talk with our partners and allies about how this is best achieved."
Greens leader Christine Milne said the US decision to increase ground troops in Iraq confirmed her fears that Australia was involved in "mission creep".
"It started off with a humanitarian response, then it moved to dropping weapons, then it moved to committing to air strikes and special forces," she told reporters.
"Now we have the Americans significantly increasing their contribution of boots on the ground."
Senator Milne called on Mr Abbott to rule out increasing the number of Australian special forces - with 200 committed on the ground in Iraq to assist local forces.
"The effort has to go into cutting off (ISIL's) financial and other supplies," Senator Milne said.
