Russia-Ukraine updates: 2 US veterans who joined Ukrainian forces missing

European Council President Charles Michel and Russian President Vladimir Putin had a call Friday. Michel said afterwards on Twitter that he "strongly urged for immediate humanitarian access and safe passage from Mariupol and other besieged cities all the more on the occasion of Orthodox Easter."

Michel also said he "firmly reiterated" the EU's support for Ukraine and "condemnation and sanctions for Russia’s aggression."

According to the Kremlin's readout of the call, Michel asked Putin to have direct contact with Ukraine President Volodymyr Zelenskyy. The Kremlin said Putin "reaffirmed the well-known position on this matter, noting that such a possibility depends, in particular, on concrete results in the ongoing negotiations between Russian and Ukrainian representatives, during which the Ukrainian side is showing inconsistency and is not ready to seek mutually acceptable solutions."

The United Kingdom announced Friday that it will soon reopen its embassy in Ukraine's capital, Kyiv.

The U.K. Embassy in Kyiv, in northern Ukraine, was forced to temporarily close in late February due to Russia's invasion. A contingent of British staff remained in western Ukraine to provide humanitarian and other support. U.K. Prime Minister Boris Johnson confirmed Friday that the embassy will reopen next week, "dependent on the security situation," according to a press release from the U.K. Foreign, Commonwealth and Development Office (FCDO).

"The extraordinary fortitude and success of President Zelenskyy and the Ukrainian people in resisting Russian forces, means we will shortly be re-opening our British Embassy in Kyiv," U.K. Foreign Secretary Liz Truss said in a statement. "I want to pay tribute to the bravery and resilience of the Embassy team and their work throughout this period."

The embassy premises in Kyiv are currently being made secure before staff return, starting with U.K. ambassador to Ukraine Melinda Simmons. The U.K. continues to advise its citizens against all travel to Ukraine, according to the FCDO.

-ABC News' Guy Davies

Russia's decision to blockade a steel plant in Mariupol "likely indicates a desire to contain Ukrainian resistance" in the strategic port city "and free up Russian forces to be deployed elsewhere in eastern Ukraine," the U.K. Ministry of Defense said Friday in an intelligence update.

The Azovstal Iron and Steel Works plant is the last holdout for Ukrainian fighters in besieged Mariupol.

"A full ground assault by Russia on the plant would likely incur significant Russian casualties, further decreasing their overall combat effectiveness," the ministry said.

Meanwhile, heavy shelling and fighting continues across eastern Ukraine's Donbas region as Russian forces seek to advance further toward settlements including Krasnyy Lyman, Buhayikva, Barvinkove, Lyman and Popasna, "as part of their plans for the region," according to the ministry.

"Despite Russia's renewed focus they are still suffering from losses sustained earlier in the conflict," the ministry added. "In order to try and reconstitute their depleted forces, they have resorted to transiting inoperable equipment back to Russia for repair."

Russian President Vladimir Putin will have a telephone conversation with European Council President Charles Michel on Friday before meeting with permanent members of the Russian Security Council, according to Kremlin spokesman Dmitry Peskov.

"Putin will now have an international conversation," Peskov told reporters Friday. "It will be the President of the European Council, Michel. And then during the day, Putin is scheduled to have an operational meeting with the permanent members of the Security Council."