US Secretary of State Antony Blinken visiting Helsinki
U.S. Secretary of State Antony Blinken gives a speech at the Helsinki City Hall, in Helsinki, Finland June 2, 2023. Lehtikuva/via REUTERS Reuters

U.S. Secretary of State Antony Blinken on Friday warned against any peace initiatives that could help legitimize Russia's seizure of Ukrainian territory, saying a "just and durable" peace effort should address accountability and reconstruction.

Delivering what U.S. officials described as a highlight speech that lays out Washington's view of 16 months of Russia's invasion of Ukraine, Blinken said over the coming weeks and months some countries were likely to call for a ceasefire.

But for any peace effort to be lasting, he laid out, it requires Ukraine's "full participation and assent" and should support Ukraine's reconstruction and recovery, with Moscow paying its share, Blinken said.

"A ceasefire that simply freezes current lines in place and enables Putin to consolidate control over the territory he seized and then rest, rearm and re-attack. That is not a just and lasting peace," Blinken said.

"It will legitimize Russia's land grab, it would reward the aggressor and punish the victim," he said.

He added that if and when Russia is prepared to discuss "true peace" Washington will respond and would be open to a broader discussion about European security that would reduce the likelihood of further conflict.

The United States has been Ukraine's top military and economic supporter, sending the country billions worth of weapons systems to defend itself against the Russian invasion that started in February 2022.

Various peace proposals to end the war have popped up in different capitals as the war has displaced millions of people, propelled food prices and made a dent in world prosperity,

Ukrainian President Volodymyr Zelenskiy made a major push to court the Global South last month in response to peace moves from some of its members. He attended the Arab League summit in Saudi Arabia on May 19, holding talks with host Crown Prince Mohammed bin Salman, Iraq and other delegations.

China, which has touted its own peace plan, sent a top envoy to Kyiv, Moscow and European capitals to discuss a "political settlement" this month. South Africa said last week Kyiv and Moscow had agreed to discuss a peace plan with African leaders. The Vatican also fleshed out a peace mission this month.

Blinken said Washington was working with Ukraine and other allies to build consensus around the core elements of a durable peace and welcomed any initiatives but said they must uphold the principles of the United Nations charter.

"We will support efforts - whether by Brazil, China, or any other nation - if they help find a way to a just and lasting peace," Blinken added.