U.S., UK resist calls for no-fly zone over Ukraine's pleas: 'Our goal is to end the war, not to expand it'
U.S. Secretary of State Antony Blinken holds a joint press conference with British Foreign Secretary Elizabeth Truss in the Benjamin Franklin Room of the State Department in Washington, D.C., March 9, 2022.

Imposing that rule in airspace where Russian planes are already flying would dramatically raise the risk of dragging NATO and the U.S. into direct combat with Russia, which experts fear could precipitate a full-on war between nuclear-armed powers.

They also have declined the increasingly strident requests from Ukraine President Volodymyr Zelenskyy to enact a no-fly zone, which could lead to the shooting down of Russian aircraft over Ukraine.

Ukraine's allies, including President Joe Biden and members of the North Atlantic Treaty Organization, or NATO, have sought to support Kyiv without putting boots on the ground.

"Our goal is to end the war, not to expand it," U.S. Secretary of State Antony Blinken said during a joint press conference alongside U.K. Foreign Secretary Elizabeth Truss.

The United States and the United Kingdom on Wednesday hardened their opposition to imposing any form of a no-fly zone in Ukraine, despite Kyiv's pleas for more protection from Russia's invasion .

"We want to make sure that [the invasion] is not prolonged, to the best of our ability, otherwise it's going to turn even deadlier, involve more people and I think potentially even make things harder to resolve in Ukraine itself," Blinken said.

Putting any U.S. troops in Ukraine, even on a limited basis, "would expand the conflict," Blinken said. "It would prolong it, it would make it much more deadlier than it already is, and that would be neither in the interests of our countries nor in the interest of Ukraine."

But he noted that "if I were in President Zelenskyy's position, I'm sure I would be asking for everything possible, in his mind, to help the Ukrainian people."

Zelenskyy himself has repeatedly called for allies to declare a no-fly zone over Ukraine, as reports mount of Russian attacks hitting civilians.

"How much longer will the world be an accomplice ignoring terror? Close the sky right now! Stop the killings!" Zelenskyy wrote Wednesday morning in a tweet accusing Russian troops of striking a hospital in the city of Mariupol in southeastern Ukraine.

Ukraine on Wednesday also accused Russia of violating a cease-fire in Mariupol, blocking civilians from evacuating the city.

The alleged hospital attack is "absolutely abhorrent, reckless and appalling," Truss said at the briefing. She maintained, however, that "the best way to help protect the skies is through antiair weaponry," rather than a no-fly zone.

"We're doing all we can to support" Ukraine, Truss said.

Blinken also poured cold water on a proposal from Poland to hand over its MiG-29 fighter jets to the U.S. — which could then transfer those jets to Ukraine — saying there was no clear "substantive rationale" for enacting the plan.

"Poland's proposal shows that there are some complexities that the issue presents when it comes to providing security assistance," Blinken said.

The "prospect of fighter jets at the disposal of the United States government, departing from the U.S. base for Germany to fly into airspace contested with Russia over Ukraine, raises some serious concerns for the entire NATO alliance," he said.

Russian President Vladimir Putin's invasion of Ukraine has prompted world leaders, international groups and private corporations to respond with an unprecedented barrage of sanctions and other penalties targeting the Russian economy, its elite leaders and oligarchs — and even Putin himself.

The Kremlin said earlier Wednesday that the U.S. is "de facto waging an economic war against Russia," after the Biden administration announced a ban on Russian oil imports.