U.S. Secretary of State Mike Pompeo has said Ukraine has "no greater friend than the United States" in its struggle against "Russian aggression."
Pompeo made the remark after meeting with the Ukrainian Foreign Minister Pavlo Klimkin in Washington on November 16.
Pompeo said the "United States will never accept Russia's attempted annexation of Crimea," and that Washington will impose "consequences until Russia returns control of the Black Sea peninsula to Ukraine."
Russia seized Crimea in March 2014, a month before it started to aid separatists in eastern Ukraine in a conflict that has killed more than 10,300 people.
The two diplomats met on the 10th anniversary of the declaration of a strategic partnership between Ukraine and the United States.
Pompeo said he and Klimkin made progress in several areas during their talks, including on security and countering Russian aggression, as well as on rule of law and humanitarian issues.
Pompeo also noted the two discussed joint efforts to stop the Nord Stream 2 project that, he said, "undermines Ukraine's economic and strategic security and risks further compromising the sovereignty of European nations that depend on Russian gas."
Nord Stream 2 is a controversial project that would expand the current Nord Stream pipeline, which passes along the bottom of the Baltic Sea to deliver Russian gas to Germany.
The United States, Poland, the Baltic states, and several other EU countries have expressed concern about Nord Stream 2 -- which avoids existing gas pipelines through Ukraine -- and the added leverage on energy security it could give Moscow.
Klimkin said the United States and Ukraine “stand shoulder to shoulder in countering Russian aggression.” He said such aggression takes many forms, both the war in Crimea and parts of Donbas in Ukraine, and in Russian efforts to undermine democratic institutions in the United States and Europe.
Klimkin also said Kyiv was grateful for U.S. support in strengthening Ukraine's defense capabilities, "both through training of our military and through providing defense equipment."
Among other things, Washington has provided Kyiv with Javelin antitank missile systems.