Nemer Hamad said another presidential aide, Nabil Shaath, was currently in Moscow to discuss preparations for Abbas's visit. The Palestinian president is also set to visit the U.S. after Moscow.
Abbas stated his intention to visit Russia following his meeting with Russian Foreign Minister Sergei Lavrov in Ramallah, in the West Bank, earlier this month.
Shaath, who arrived in Moscow on Monday, said he planned to meet with Russia's Lavrov and other top officials to discuss the agenda for Abbas's visit.
"I will discuss with Russian Foreign Minister Sergei Lavrov issues concerning the upcoming visit to Moscow by Palestinian President Mahmoud Abbas, preparations for the Moscow meeting on the Middle East and all aspects of our bilateral relations," Shaath said.
Following talks with Lavrov earlier in the month, Abbas said the Palestinian National Administration (PNA) backed Russia's plans to hold an international meeting on the Middle East in Moscow.
Shaath also said that the Moscow conference on the Middle East could take place in May, but that the exact date would be "set by the Russian authorities."
Abbas's Fatah movement was expelled from the Gaza Strip following clashes with the hard-line Islamic group Hamas last June. It receives financial assistance from the West, while Gaza is fully isolated and boycotted by the PNA, the U.S. and Israel.