Republican United States Senator Lindsey Graham has died at the age of 71. The news was confirmed by his office, which announced that he passed away on Saturday after a sudden illness.

"During this extremely difficult time, Senator Graham's family thanks you for your prayers and requests respect for privacy," the official statement said.

According to US media, emergency services responded to a cardiac arrest call at Graham's Washington apartment on Saturday evening.

Just a day earlier, Graham had returned from a visit to Ukraine, where he met with President Volodymyr Zelenskyy in Kiev. He was also scheduled to appear on NBC News' "Meet the Press" on Sunday.