beirut hezbollah leader sayyed hassan nasrallah say sunday unite state serve interest islamic state prevent syrian army ally advance areas eastern syria american jet year target pro-government militias eastern syria advance towards washington local ally nasrallah say unite state delay syrian military battle retake territory islamic state american air force areas prevent syrian army ally advance areas control islamic state say leader hezbollah lebanese shi ite movement designate washington terrorist group americans work hind battle islamic state say speech part commemoration hezbollah fighters kill clash islamic state comment come senior u.s. official say president donald trump consider put sanction iran support hezbollah u.s. congress prepare consider tight sanction hezbollah battlefield situation syrian complex comprise civil war pit syrian president bashar al-assad government rebel well two separate campaign islamic state syrian army back russia iran shi ite militias include hezbollah advance islamic state offensive across central syrian desert recent months unite state meanwhile lead rival international coalition sunni jihadists include alliance kurdish arab militias russia unite state put place measure prevent outright conflict two offensives islamic state time fire security source lebanon say hezbollah lose hundreds fighters syria since enter conflict support assad 2013 rebel group last week islamic state counter attack syrian army ally kill number hezbollah fighters include senior commander ali al-hadi al-asheq hezbollah leader say u.s. action aid islamic state syria