Matthew Pottinger, also the senior director for Asia at the US National security Council, will head the delegation.
"As we always say, the Belt and Road is an open and inclusive initiative," Geng told a daily news briefing. "We welcome all parties to participate."
The US embassy in Beijing said Alan Turley of the US Commerce department also will be part of the delegation, Reuters reported. Turley is the department's deputy assistant secretary for China.
Representatives from other developed countries also will attend. former French prime minister Jean-Pierre Raffarin was chosen by French president-elect Emmanuel Macron as his special representative to the forum, Geng said.
The British delegation will be led by Chancellor of the Exchequer Philip Hammond and the German delegation by Minister for Economic Affairs Brigitte Zypries. In addition, European Commission Vice-President Jyrki Katainen will attend forum activities.
The Republic of Korea's new president, Moon Jae-in, has sent Park Byeong-seug, a veteran member of Parliament and a senior official of Moon's Democratic Party, to the forum on behalf of the ROK government, Geng said.
He added that Japan's delegation will be led by Toshihiro Nikai, secretary-general of the ruling Liberal Democratic Party.
