FOR ISRAELI TROOPS TO WITHDRAW FROM SOUTHERN LEBANON.

TUESDAY IS THE AGREED UPON DATE - - BUT ISRAEL ALREADY MISSED ONE PREVIOUS DEADLINE AT THE END OF JANUARY.

AND IT'S INDICATED IT WILL REMAIN IN SOME STRATEGIC AREAS ALONG THE BORDER, RAISING FEARS OF A PROLONGED OCCUPATION.

U.S. CENTRAL COMMAND -- WHICH CHAIRS THE CEASEFIRE COMMITTEE - - REITERATED ON FRIDAY IT EXPECTS ISRAEL TO HAND OVER CONTROL OF ALL POPULATION CENTERS BY THE TUESDAY DEADLINE.

SPECIAL CORRESPONDENT SIMONA FOLTYN HAS OUR REPORT FROM SOUTHERN LEBANON - WHERE SHE EMBEDDED WITH U.N.

FORCES.

SIMONA: IN SOUTHERN LEBANON YOU WHEN PEACEKEEPERS WALK OVER -- WATCH OVER A FRAGILE CEASE-FIRE.

HE LEADS THE BATTALION HERE.

>> WE ARE ABOUT SIX TO SEVEN KILOMETERS FROM THE BLUE LINE.

SIMONA: THAT IS THE DEMARCATION LINE SEPARATING LEBANON AND ISRAEL.

FOR DECADES THIS MISSION HAS BEEN STATIONED HERE TO KEEP HOSTILITIES BETWEEN ISRAEL AND HEZBOLLAH AT BAY.

>> OUR JOB IS TO BE THE EYES AND EARS OF THE INTERNATIONAL COMMUNITY AND PASS ON WHATEVER INFORMATION WE CAN SEE ON THE GROUND IN RELATION TO VIOLATIONS.

SIMONA: THE VIOLATIONS HAVE BEEN MANY.

ALMOST THREE MONTHS AFTER THE CEASE-FIRE CAME INTO EFFECT, ISRAEL STILL OCCUPIES LEBANESE TERRITORY AND IS LIKELY TO STAY PAST A SECOND DEADLINE.

THE DELAYS HAVE SPARKED FIERCE OPPOSITION FROM LEBANON'S NEWLY FORMED GOVERNMENT.

UNIFIL HAS BEEN CAUGHT IN THE MIDDLE.

>> IT HAS BEEN TENSE, I'M PRETTY DOUBLE AND THERE HAS BEEN MOVEMENT OF THE CIVILIAN POPULATION OUT OF THE AREA OF OPERATIONS.

A LOT OF ACTIVITY HERE.

IT HAS BEEN DIFFICULT TO OPERATE AS A U.N. PEACEKEEPING FORCE IN THOSE CONDITIONS.

SIMONA: WHILE HEZBOLLAH HAS STOPPED FIRING ROCKETS INTO NORTHERN ISRAEL, THE LEBANESE GOVERNMENT ACCUSES ISRAEL OF HUNDREDS OF ATTACKS ON LEBANESE SOIL SINCE THE TRUCE BEGAN IN NOVEMBER.

UNIFIL DOES NOT HAVE THE MANDATE TO ENFORCE THE CEASE-FIRE.

ITS JOB IS TO MONITOR AND REPORT VIOLATIONS.

EVEN THAT HAS BECOME MORE CHALLENGING IN RECENT MONTHS AS IT FACES GROWING MOVEMENT RESTRICTIONS, ESPECIALLY FROM THE ISRAELI SIDE.

TO ACCESS AREAS -- IS REALLY AREAS UNDER UNIFIL, THEY MUST GET PERMISSION.

>> IF WE WANT TO GO TO A U.N.

POSITION WE GO THROUGH THAT VILLAGE OR AROUND THE VILLAGE.

WE REQUEST PERMISSION TO TRAVEL.

FREEDOM OF MOVEMENT FOR THE U.N. IS DIFFICULT AT THE MOMENT.

THERE ARE ROADBLOCKS, CONDITIONS SET THAT MEANS WE CAN'T GO INTO CERTAIN LOCATIONS.

THAT IS FRUSTRATING AS A COMMANDER.

SIMONA: AS A RESULT UNIFIL WAS UNABLE TO TAKE US CLOSE TO THE BLUE LINE WHERE ISRAELI TROOPS ARE STATIONED.

INSTEAD WE HEADED TO A NEARBY TOWN, PASSING THROUGH VILLAGES WHERE HEZBOLLAH ENJOYS WIDESPREAD SUPPORT.

THIS HAS HISTORICALLY BEEN A HEZBOLLAH STRONGHOLD AND THERE IS SUSPICION BY LOCALS TO UNIFIL WHO SOME PERCEIVE AS EXCITING WITH ISRAEL.

PEACEMAKERS ARE DOING THEIR BEST TO BUILD TRUST WITH LOCAL COMMUNITIES.

THE PEACEKEEPERS VISIT A GIRL'S ORPHANAGE DAMAGED IN AN ISRAELI STRIKE.

THEIR RECTOR IS GRATEFUL FOR SUPPORT, BUT SUCH POSITIVE ATTITUDES TOWARD UNIFIL ARE RARE.

>> DURING THE CONFLICT, THE RECENT CONFLICT, THE PEOPLE DID NOT FEEL THAT UNIFIL WAS SUPPORTIVE TO THEM BECAUSE THEIR HOUSES, ALL THE HOUSES, WERE BLOWN UP AND DAMAGED.

WHAT WAS NOT BLOWN UP WAS BURNED IN FRONT OF UNIFIL EYES AND UNIFIL DID NOT OR COULD NOT DO ANYTHING.

SIMONA: DISTRUST HAS GROWN IN MONTHS AS ISRAEL REPEATEDLY VIOLATES THE CEASE-FIRE WITH LITTLE CONDEMNATION FROM THE INTERNATIONAL COMMUNITY.

>> SOME PEOPLE HAVE THAT FEELING THAT, WHY DOES UNIFIL NOT SEE BOTH SIDES EQUALLY?

ALL THE PRESSURE IS PUT ON THE LEBANESE SIDE.

SIMONA: AS PART OF THE TRUCE HAS BULLET IS TO DISARM SOUTH OF THE RIVER, IN LINE WITH A 2006 U.N.

RESOLUTION NEVER AND PLUMMETED.

ISRAEL IS SAYING LEBANON HAS NOT KEPT ITS PART OF THE DEAL.

HOW EASY IS IT FOR YOU TO VERIFY IF HEZBOLLAH HAS DISARMED SOUTH OF THAT RIVER?

>> IT IS DIFFICULT TO ANSWER.

WHAT WE HAVE SEEN IN WEEKS IS A DECREASE IN KINETIC ACTIVITY.

SIMONA: MANY OF THE FIGHTERS ARE FROM SOUTHERN LEBANON AND CAN BLEND INTO THE CIVILIAN POPULATION.

IS IT POSSIBLE TO DIFFERENTIATE BETWEEN FIGHTERS AND CIVILIANS?

>> WHEN ANY ARMED ELEMENT IS EMBEDDED IN THE COMMUNITY, IT IS IMPOSSIBLE TO DETERMINE WHO IS A FIGHTER AND WHO IS JUST A NORMAL CIVILIAN.

SIMONA: ISRAEL HAS SAID IT WILL REMAIN HERE UNTIL LEBANON UPHOLDS ITS COMMITMENTS UNDER THE CEASE-FIRE.

MANY FEAR THIS COULD OPEN THE DOOR FOR INDEFINITE ISRAEL PRESENCE AND PERHAPS GIVE HEZBOLLAH REASON TO TAKE UP ARMS AGAIN.

FOR PBS NEWS WEEKEND, SIMON