Washington, PTI: US President Donald Trump greeted Prime Minister Narendra Modi on his 70th birthday, praising him as a "great leader and loyal friend". Prime Minister Modi, born on September 17 in 1950, turned 70 on Thursday. "I would like to extend best wishes and a very happy 70th birthday to the Prime Minister of India, @narendramodi. Many happy returns to a GREAT LEADER and loyal friend!" Trump tweeted Thursday afternoon local time. He also posted a photograph of him and First lady Melania Trump with Prime Minister Modi at the 'Namaste Trump' event. The two leaders had their hands raised and clenched before a 125,000-strong crowd who had gathered to welcome the US president on his first India visit at Motera cricket stadium in Ahmedabad in February this year. At the event, Prime Minister Modi had said that a "new history" was being created. Modi and Trump enjoy a "special relationship" and have been working on a number regional and global issues. They frequently talk over the phone and the countries have had an unprecedented level of co-operation even during the coronavirus pandemic. India supplied hydroxychloroquine to the US in the early stages of the pandemic and Trump ordered ventilators to India. The two countries are also collaborating on development of vaccine and therapeutics. On Thursday, Lisa Curtis, the deputy assistant to the US president, told a top American think-tank the Trump administration has elevated the relationship with India and solidified the growing partnership "in ways not seen in any other US administration". “The joint statement signed by President Trump and PM Modi following Trumps’ visit to India in February is testament to this administration's commitment to building this vital partnership," Curtis said. "Whether we are talking about increasing collaboration to develop therapeutics and vaccines to combat Covid-19; increasing defence cooperation, such as India's recent decision to purchase US multi-role and attack helicopters worth USD 3 billion; or enhancing collaboration on cyber security, the US-India relationship has never been better,” she said. Trump was among a host of world leaders, including Russian President Vladimir Putin, British Prime Minister Boris Johnson and German Chancellor Angela Merkel, who wished Modi on his birthday and lauded him for strengthening ties with their countries.