The United States received Russia's response to Washington's security proposals on Thursday when it was delivered to U.S. Ambassador to Russia John Sullivan in Moscow, a senior U.S. State Department official said.
The official did not elaborate.
Russian Foreign Minister Sergei Lavrov said earlier Moscow's reply on the issue of security guarantees would come on Thursday, the TASS news agency reported.
Sullivan visited the foreign ministry building and left shortly afterwards without talking to the press, TASS reported.
Moscow will make the letter public a few hours after handing it over to the United States, Lavrov said. Russia has demanded that Ukraine not be allowed to join NATO, something that Washington and Brussels have so far refused to promise.
Ukraine wants NATO membership, its ambassador to Washington reaffirmed on Thursday.
"Membership in NATO is our goal, and we work day and night to get there," Ambassador Oksana Markarova said in an interview with CNN.
(Reporting by Susan Heavey and Doina Chiacu; Editing by Chizu Nomiyama)
