In a diplomatic blow to Russia, the United Nations will continue to view Crimea as part of Ukraine in line with a General Assembly resolution adopted last week, the United States and Western diplomats said on Wednesday.

The 193-nation assembly on March 28 declared invalid the Moscow-backed referendum across Crimea that led to the Black Sea peninsula's secession from Ukraine and annexation to Russia. There were 100 votes in favor, 11 against, 58 abstentions and 24 countries that did not vote.

Although the resolution is not enforceable in the way that UN Security Council resolutions can be, its adoption means the entire United Nations system will continue to recognize Kiev's authority over the Crimean peninsula and ignore Russian claims to the territory.

"It (the resolution) has real legal consequences because now, legally, the UN finding ... is that the (Crimean) referendum was illegitimate," U.S. Ambassador to the United Nations Samantha Power told the Senate Appropriations Committee in Washington on Wednesday.

That determination, several Western diplomats said on condition of anonymity, has been confirmed by the UN Office of Legal Affairs (OLA) in the wake of the assembly vote.

OLA routinely gives legal advice for the UN system on how the world body should interact with and refer to disputed territories.

A senior Western diplomat said last week's General Assembly resolution "has solidified the UN position" that Kiev's authority over Crimea continues to be recognized.

"The OLA has now made clear that as far as the UN system is concerned, Crimea remains part of Ukraine," he said. "That is obviously significant for a whole variety of reasons."

The Russians, he said, were already trying to assert their control over Crimea throughout the UN system, specifically with at the International Maritime Organization and the International Postal Union.

"The IPU is a big one, the International Postal Union, where the Russian Postal Service is claiming the only right to deliver post in Crimea," the diplomat told reporters.

"Now that there is this clear resolution by the General Assembly, the system can push back and say no, I'm sorry, as far as the UN is concerned, Crimea remains part of Ukraine," the diplomat said.

Several diplomats said UN Secretary-General Ban Ki-moon was backing Ukrainian claims to Crimea in his public remarks on Friday when asked how the world body looked upon Russia's annexation of the territory. He told reporters, "The United Nations is guided by the General Assembly resolution."

Ukraine's former Russian-backed president, Viktor Yanukovych, was ousted in February after a crackdown on demonstrations in Kiev that left dozens of people dead. This prompted Moscow to send in troops and seize the largely Russian-speaking peninsula.

The General Assembly resolution approved last week, which echoed a text Moscow vetoed last month in the Security Council, called on countries to not recognize Crimea as anything other than Ukrainian territory.

The assembly resolution dismissed Crimea's March 16 referendum as "having no validity, (and) cannot form the basis for any alteration of the status of the Autonomous Republic of Crimea or of the City of Sevastopol."

