Russia on Tuesday accused the US of direct involvement in the Ukraine war, while the first ship carrying Ukrainian grain to world markets since Moscow's invasion continued its passage to Lebanon without problems.
Russia said it was responding to comments by Vadym Skibitsky, Ukraine's deputy head of military intelligence, about the way Kyiv used US-supplied long-range HIMARs rocket launch systems based on what he called excellent satellite imagery and real-time information.
Skibitsky told Britain's Telegraph newspaper there was consultation between US and Ukrainian intelligence officials before strikes and that Washington had an effective veto on intended targets, though he said US officials were not providing direct targeting information.
Russia's defence ministry, headed by a close ally of President Vladimir Putin, said the interview showed that Washington was directly involved despite repeated assertions that it was limiting its role in the conflict to arms supplies because it did not want a direct confrontation with Moscow.
"All this undeniably proves that Washington, contrary to White House and Pentagon claims, is directly involved in the conflict in Ukraine," the Russian defence ministry said in a statement.
"It is the Biden administration that is directly responsible for all Kyiv-approved rocket attacks on residential areas and civilian infrastructure in populated areas of Donbas and other regions, which have resulted in mass deaths of civilians," the defence ministry said.
There was no immediate reaction to the defence ministry's allegations from the White House or Pentagon.
Ukraine and the West accuse Russia of carrying out devastating missile attacks on civilian targets on an almost daily basis. Both sides deny deliberately targeting civilians.
Supplies of sophisticated long-range weapons systems from Western nations to Ukraine are seen as vital if Kyiv's forces are to turn the tide of the war, in which Russia relies heavily on long distance bombardments of urban areas.
Russia's verbal attack on Washington came after Turkey said that the first ship carrying Ukrainian grain since Russia's invasion blocked exports more than five months ago was on track to safely arrive in Istanbul on Tuesday night.
The vessel's departure on Monday from the Ukrainian port of Odesa for Lebanon via Turkey under a safe passage deal has raised hopes of further such departures which could help ease a burgeoning global food crisis.
Turkey expects roughly one grain ship to leave Ukrainian ports each day as long as the safe passage agreement holds, a senior Turkish official, who asked to remain anonymous, said on Tuesday.
The United Nations has warned of the risk of multiple famines this year because of the war in Ukraine.
Monday's sailing was made possible after Turkey and the United Nations brokered a grain and fertiliser export agreement between Russia and Ukraine last month - a rare diplomatic breakthrough in a conflict that has become a drawn-out war of attrition since Russian troops poured over the border on Feb 24.
Ukrainian President Volodymr Zelensky in his nightly address late on Monday called the ship's departure "the first positive signal," but warned it was too early to draw conclusions or predict how things would play out.
"We cannot have illusions that Russia will simply refrain from trying to disrupt Ukrainian exports," said Zelensky.
Ozcan Altunbudak, Turkey's representative at a coordination centre created to oversee the restart of Ukrainian grain exports, said on Tuesday the vessel, the Sierra Leone-flagged ship Razoni, was on track to anchor at Istanbul on Tuesday night.
The only issue so far was a slight delay caused by bad weather, he said. The ship, which is carrying 26,527 tonnes of corn, was due to arrive in Istanbul at around midnight local time.
It will then be inspected by Russian, Turkish, Ukrainian and UN officials under the terms of the safe passage agreement before continuing its journey to the Lebanese port of Tripoli, its planned final destination.
There are other hurdles to overcome however before millions of tonnes of Ukrainian grain can leave, including clearing sea mines and creating a framework for vessels to safely enter the conflict zone and pick up cargoes.
Known as Europe's breadbasket, Ukraine hopes to export 20 million tonnes of grain held in silos and 40 million tonnes from the harvest now under way, initially from Odesa and nearby Pivdennyi and Chornomorsk, to help clear the silos for the new crop.
Russia has called the Razoni's departure "very positive" news. It has denied responsibility for the food crisis, saying Western sanctions have slowed its exports.
Russia and Ukraine accuse each other of laying mines that now float around the Black Sea and represent a hazard to shipping.
Also on Tuesday Russia publicly spelled out its solidarity on Taiwan with China, with whom is enjoys a close partnership, ahead of a possible visit there by US House of Representatives Speaker Nancy Pelosi.
Russian Foreign Ministry spokeswoman Maria Zakharova called the possible visit "a provocation" and said that Moscow supported Beijing's One China principle and opposed Taiwanese independence "in any form."