(S (S (NP (NP (NP (BASENP (NNP Iran) (POS 's)) (BASENP (JJ chief) (JJ nuclear) (NN negotiator))) (COMMA ,) (BASENP (NNP Ali) (NNP Larijani))) (CONJP (COMMA ,) (CC and)) (BASENP (NNP European) (NNP Union) (JJ foreign) (NN policy) (NN chief) (NNP Javier) (NNP Solana))) (VP (VP (VBP have) (VP (VBN executed) (NP (NP (BASENP (NN four) (NNS rounds)) (PP (IN of) (BASENP (NNS negotiations)))) (PP (IN on) (NP (BASENP (NNP Iran) (POS 's)) (BASENP (JJ nuclear) (NN program))))))) (CC but) (VP (VBP have) (VP (VBN failed) (S (VP (TO to) (VP (VB make) (BASENP (DT a) (NN breakthrough))))))))) (PERIOD .))