WASHINGTON -- The United States announced a formal policy reaffirming its rejection of Russia's annexation of Ukraine's Crimea Peninsula, with Secretary of State Mike Pompeo blasting Moscow for seeking “to undermine a bedrock international principle shared by democratic states.”

Pompeo's announcement July 25, released an hour before his scheduled testimony to the Senate Foreign Relations Committee, followed recent conflicting remarks by President Donald Trump and administration officials about whether Washington was moving to reverse a policy in place since Russia's seizure of the Black Sea peninsula in 2014.

“The United States reaffirms as policy its refusal to recognize the Kremlin’s claims of sovereignty over territory seized by force in contravention of international law,” said Pompeo’s statement, titled the Crimea Declaration.

“In concert with allies, partners, and the international community, the United States rejects Russia’s attempted annexation of Crimea and pledges to maintain this policy until Ukraine’s territorial integrity is restored,” it added.

It said the United States called on Russia to respect the “principles to which it has long claimed to adhere and to end its occupation of Crimea.”

In the later testimony before the Senate committee, Pompeo said there will be “no relief” for Moscow from sanctions imposed by the United States after the attempted annexation “until Russia returns control of the Crimean Peninsula to Ukraine.”

Moscow in 2014 forcibly annexed Ukraine’s Crimean Peninsula, a move condemned by the international community. It has also backed separatists in eastern Ukraine fighting against the Kyiv government in a war that has killed more than 10,300 people -- actions that led to U.S. and EU sanctions being imposed against Moscow.

It wasn't immediately clear what the declaration would entail, but Pompeo in his announcement referenced the Welles Declaration of 1940. That act was a decision by the United States not to recognize the Soviet annexation of the three Baltic states of Estonia, Latvia, and Lithuania. That policy lasted for 50 years and outlasted the Soviet Union.

Nonrecognition of the Crimea annexation was also the policy of the previous administration of President Barack Obama, but Pompeo's remarks appear to be an effort to clearly state the current administration's attitude after the recent diplomatic confusion.

Asked by reporters on June 29 whether reports about him ending Washington's longstanding opposition to the Crimea annexation were true, Trump replied: "We're going to have to see."

Trump answered in a similar manner when asked whether he would consider lifting U.S. sanctions on Russia.

"We'll see what Russia does," Trump said.

The remarks caused concerns throughout Europe, and particularly in Ukraine, that Trump could overturn U.S. policy and effectively accept the first major land grab on the continent since World War II.

The Ukrainian Foreign Ministry tweeted after Pompeo’s declaration that “we welcome the U.S. position on territorial integrity of Ukraine and nonrecognition of Russia’s attempt to annex Crimea…No one has the right to change the borders of free sovereign states by force."

In a brief statement, Russian Foreign Ministry spokeswoman Maria Zakharova responded by saying, “We know the value of such momentous declarations.”

Maja Kocijancic, the spokeswoman for EU foreign policy chief Federica Mogherini, said in a statement that the U.S. declaration “illustrates the U.S.'s continued strong and principled stance on Russia's illegal annexation of Crimea and Sevastopol and violation of Ukraine's sovereignty and territorial integrity.”

She said the EU remains “firmly committed to Ukraine's sovereignty and territorial integrity and to fully implementing our nonrecognition policy, including through restrictive measures.”

Britain's Foreign Office said in a statement that "the U.K. echoes the United States’ firm statement of opposition to Russia’s illegal annexation of Crimea. The U.K. position is clear: We condemn Russia’s continued breach of international law; Crimea is Ukrainian territory. We remain fully committed to upholding the sovereignty and territorial integrity of Ukraine within its internationally recognized borders."

In the face of Russian aggression, Ukraine has relied on U.S. diplomatic, financial, and military support that has so far remained steady and featured the delivery of lethal Javelin antitank missile systems and $200 million in additional security funding to boost defensive capabilities.

The announcement also comes as Trump continues to insist that no president has ever been tougher on Russia amid criticism from Democrats and others that he has been too complimentary toward Putin and has overlooked alleged wrongdoing by Moscow regarding meddling in elections and activities in Ukraine, Syria, and elsewhere.

In his statement to the Senate panel, Pompeo said Trump’s recent summit in Helsinki with Putin and their continuing dialogue was in the interest of the United States and the “whole world.”

Trump “strongly believes that now is the time for direct communication in our relationship in order to make clear to President Putin that there is the possibility to reverse the negative course of our relationship. Otherwise, the administration will continue imposing tough actions against Russia in response to its malign activities,” Pompeo said.

“We can’t make progress on issues of mutual concern unless we are talking about them,” he added.

He specifically cited issues involving Ukraine, the fight against terror, the civil war and humanitarian aid in Syria, security for Israel, and shutting down all of Iran’s “malign activity.”

“In Helsinki, we sought to explore whether Russia was interested in improving the relationship, but made clear that the ball is in Russia’s court. We defended America’s fundamental strategic interests in Syria and Ukraine, and I personally made clear to the Russians that there will be severe consequences for interference in our democratic processes,” Pompeo told the committee.

Pompeo said Trump has accepted the U.S. intelligence community’s conclusion that Russia meddled in the 2016 U.S. presidential election.

“He has a complete and proper understanding of what happened,” Pompeo added.

Pompeo also said that after the Trump-Putin summit, U.S. policy on Russian sanctions is "completely unchanged" and told the senators that NATO "will remain an indispensable pillar of American national security."

Trump has called on the Western military alliance members to increase their level of defense spending and reduce their dependence on U.S. funding.