The United States has invited Russian President Vladimir Putin to attend the Group of 20 summit in Miami in December, Secretary of State Marco Rubio said on September 23, as the Trump administration is seeking steps to reduce fighting in Ukraine. “We've invited President Putin to the G20," Rubio told reporters after meeting Russian Foreign Minister Sergei Lavrov on the sidelines of the UN General Assembly in New York. "We think it's an opportunity for him to engage not just with the president but with other world leaders.” The invitation…