Madrid, May 30 : Spanish Prime Minister Pedro Sanchez met with NATO Secretary General Jens Stoltenberg ahead of the 40th anniversary of Spain's entry into the alliance on Monday. The Prime Minister's office on Sunday said the meeting took place at the country estate of Quintos de Mora in Los Yebenes, to the south of the Spanish capital, with Sanchez and Stoltenberg holding working meetings ahead of the forthcoming NATO Summit, which will be held in Madrid on June 29-30, Xinhua news agency reported. Sanchez tweeted, "Working weekend with Jens Stoltenberg, prior to the commemoration of the 40th anniversary of Spain's accession to NATO. Prepared to host the next NATO Summit, at a historic moment for the Alliance in defense of peace and security." Monday's ceremony will be attended by Sanchez, Stoltenberg and King Felipe VI of Spain. /IANS