When asked about Assad's visit to the UAE, US State Department spokesperson Ned Price said Washington was profoundly disappointed.
Dmytro Kuleba delivered a powerful message at an extraordinary meeting of NATO Foreign Ministers.
The visit follows her completion of 'The Walk', a four-month travelling festival of art and hope over 8,000 km from the Syrian border to Manchester.
Army Major John Rigsbee, a spokesman for US Central Command, said in a statement that Abdul Hamid al-Matar was killed by a drone strike.
Twelve-year-old Zaza battled an opponent more than three times her age in 39-year-old Liu Jia in the women's singles preliminary round.
In a statement, the US military said it targeted operational and weapons storage facilities at two locations in Syria and one location in Iraq.
Inspired by his father Abdul Majeed, a surgeon who always helped the downtrodden as well as his then mother-in-law Nimmi Sheriff, Dr Majeed joined MSF in September 2014.
Tuesday's blast was one of the deadliest to hit a region under the control of Turkish-backed forces.
The outbreak has infected some 580,000 people and killed over 26,000 around the world after emerging in China in December last year.
Russian vetoes, often backed by China, have chronically crippled UN action in Syria.