Kerry says troops in Syria to only fight Islamic State; won't rule out further US escalation

US Secretary of State John Kerry, left, and Kyrgyz Foreign Minister Erlan Abdyldaev shake hands during a ribbon cutting ceremony at the US Embassy on Saturday Oct. 31, 2015 in Bishkek. Kerry arrived in Central Asia for a five-day, five-nation tour of the "Stans", Kyrgyzstan, Uzbekistan, Kazakhstan, Tajikistan and Turkmenistan, to reassure them they will not be forgotten. (Brendan Smialowski / Pool via AP) (The Associated Press)

US Secretary of State John Kerry laughs with Kyrgyz Foreign Minister Erlan Abdyldaev upon his arrival at Manas International Airport in Bishkek. Kyrgyzstan on Saturday, Oct. 31, 2015. Kerry is on an official visit to the central Asian nations. (Brendan Smialowski/Pool Photo via AP) (The Associated Press)

U.S. Secretary of State John Kerry says American special operations troops being sent to Syria will only fight Islamic State militants and won't become involved in the long-running civil war.

Kerry calls IS a threat to every nation and says U.S. policy is clear — the group must be defeated.

Kerry isn't ruling out a further U.S. escalation of the fight, saying he can't predict the future.

The Obama administration is sending up to 50 special operations troops to assist Kurdish and Arab forces in northern Syria. It's the first pledge of American military boots on the ground in Syria.

Kerry spoke Saturday at a news conference in Kyrgyzstan alongside the country's foreign Minister, Erlan Abdyldaev.