New Delhi, Aug 25 : Prime Minister Narendra Modi, who is on a day-long visit to Athens, met Greek President Katerina Sakellaropoulou on Friday during which he spoke about the success of the Chandrayaan-3 mission. Modi's trip to Greece is the first by an Indian Prime Minister in 40 years. In a tweet, the Prime Minister said: "Glad to have met President Katerina Sakellaropoulou in Athens. We discussed several issues which will strengthen the India-Greece friendship. We also discussed ways to boost sustainable development. She congratulated India on the success of Chandrayaan-3." Modi went on to say that the "success of Chandrayaan-3 is not only of India alone but it is a success for the whole of humankind". "The results of the data collected by the Chandrayaan-3 mission will help the entire scientific fraternity and humankind." After their meeting, President Sakellaropoulou conferred Modi with the Grand Cross of the Order of Honour. "I thank President Katerina Sakellaropoulou, the Government and people of Greece for conferring upon me The Grand Cross of the Order of Honour. This shows the respect the people of Greece have towards India," the Prime Minister said in another tweet. Following his arrival on Friday morning, he also paid tributes at the 'Tomb of Unknown Soldier'. This is also Modi's maiden visit to Greece. The Prime Minister is also scheduled to hold interactions with the Greek business community, Indian diaspora and prominent personalities. /IANS