I must ticket a 4 continent OWE in first ASAP from NRT.

Here itinerary
NRT-JFK-LAX-ORD-SJU-ORD-LAX-SCL-GRU-SCL-GRU-EZE-xLAX ( on Lan Chile flight 600 which makes a stop in SCL and LIM but there is only one flight number! )-LHR-TLV-LHR-SIN-HKG-NRT-HKG-NRT

My question is this.....can I transit from South America to Europe via North America by going through LAX if the stop is less than 24 hours? Thanks.....also, even though Lan chile flight 600 has two stops before LAX...is it considered one flight segment???