Biden Mulls Sending Senior US Official to UkraineWASHINGTON — U.S. President Joe Biden said Thursday that he's considering sending a senior U.S. official to Ukraine, a high-profile visit that would underscore Washington's commitment to the besieged nation. When asked whether he would dispatch an official, Biden replied, "We're making that decision now." "Are you ready to go?" Biden joked to a reporter. "Are you?" the reporter responded. "Yeah," the president said. Earlier in the week, White House press secretary Jen Psaki said Biden did not have plans to visit Ukraine himself. British Prime Minister Boris Johnson recently made a surprise visit to Ukraine's capital, as have other European leaders. As fighting continued in eastern Ukraine on Thursday, the 50th day of Moscow's invasion, Russia announced that the flagship of its Black Sea fleet, the Moskva, sank as it was being towed to port. The ship was heavily damaged by an onboard explosion, and the crew of about 500 sailors had been evacuated. The Russian Defense Ministry blamed a fire that detonated ammunition on board the guided-missile cruiser, but Ukraine said it hit the ship in a missile attack. "I cannot confirm the Ukrainian reports that it was hit by a missile," said Pentagon press secretary John Kirby on Thursday. "But we are also not in a position to refute that it could have been a Ukrainian missile which struck the ship. We just don't have perfect visibility on exactly what happened." Biden's national security adviser, Jake Sullivan, said the vessel was badly damaged on Wednesday as a result of either "incompetence" or a successful attack by the Ukrainians. "We've been in touch with the Ukrainians overnight, who said they struck the ship with anti-ship missiles," Sullivan told an audience at the Economic Club of Washington. "We don't have the capacity at this point to independently verify that, but certainly the way that this unfolded is a big blow to Russia." Meanwhile, the verbal duel continued to escalate between Moscow and Washington. Russian President Vladimir Putin on Thursday warned European countries looking to replace energy purchases from Russia that it would be "quite painful for the initiators of such policies." The Russian leader said, "Supplies from other countries that could be sent to Europe, primarily from the United States, would cost consumers many times more" and would "affect people's standard of living and the competitiveness of the European economy." The European Union is dependent on Russia for 40% of its natural gas and 25% of its oil. And Russia said that if Finland and Sweden revoked their longtime neutral stance between Moscow and the West and joined the U.S.-dominated NATO military alliance, then Russia would move nuclear weapons closer to the two Northern European countries. Meanwhile, the U.S. continues to flood Ukraine with weapons. Biden informed Ukrainian President Volodymyr Zelenskyy on Wednesday of a new $800 million U.S. arms shipment. Later, in a statement, Biden said, "The Ukrainian military has used the weapons we are providing to devastating effect. The United States will continue to provide Ukraine with the capabilities to defend itself." The Pentagon said the new tranche of weaponry includes 500 Javelin missiles; 300 Switchblade drones; 300 armored vehicles; 16 helicopters; chemical, biological and nuclear protective gear; and 30,000 sets of body armor and helmets. The U.S. is also providing an unknown quantity of anti-personnel munitions, which are configured to be only manually detonated.