Senator Lindsey Graham died at the age of 71. He suffered from a heart ailment caused by the hardening of arteries, his office shared. The Republican from South Carolina was in Ukraine just before his demise, leading to questions being asked about when he returned to the US. Senator Lindsey Graham was in Ukraine before his demise on July 11. (AP Photo)Notably, Graham, a defense hawk, was a staunch supporter of Ukraine and Israel, and an opponent of Iran. He was in Kyiv on Friday, where he met Ukraine President Volodymyr Zelenskyy, where the two discussed Ukraine's air defense ​needs and a Russia sanctions bill. A page on X providing information about the military conflict between Ukraine and Russia claimed that Graham had died in Kyiv, not Washington DC. “Lindsey Graham died in Kyiv, not Washington, DC. He arrived in Kyiv on the morning of 10 July. The trip to Kyiv entails flying to Poland and then taking a 8-10 hour train ride. He was visiting a drone factory in Kyiv that was hit by the Russians. He did not have enough time to depart Ukraine on Saturday morning, take the train to Poland and then catch a flight back to DC,” the page wrote. When did Lindsey Graham return from Ukraine?However, Graham is believed to have returned to the US on Saturday, July 11 – hours before his demise. The Wall Street Journal noted that emergency responders had arrived at Graham's Capitol Hill home on Saturday night, indicating the Senator was back stateside. The publication further reported that Graham's last public appearance had been outside St. Michael’s golden-domed monastery in Kyiv. Also Read | Lindsey Graham spoke to Trump in final hours, joked before death: 'I can’t die now'Following Senator Graham's demise, President Donald Trump ordered that flags would be flown at half-mast across the US. Notably, Graham had initially been a vocal critic of Trump but later went on to become one of his staunchest supporters. “I just can’t believe it,” Trump said. “He was like a member of the family.”Who will replace Lindsey Graham in the Senate? Graham's death comes ahead of the primaries in November, and while he was set to go up against the Democrat candidate Annie Andrews for the South Carolina seat, his death will necessitate that a special primary election is held. Some of the names that have reportedly come up as possible replacements are Trey Gowdy, Nancy Mace, former Governor Nikki Haley, and Ralph Norman. South Carolina Republican Governor Henry McMaster has the powers to name a replacement for the rest of the term.