Ukraine’s Foreign Minister Dmytro Kuleba on Sunday alleged that Russia has ignored its requests to explain the build-up of troops along its border.

Kuleba said that Ukraine has called for a meeting with Russia and other members of the Organization for Security and Co-operation in Europe, or OSCE.

The OSCE, which looks at matters of arms control, protection of human rights and freedom of the press, has 57 members including Russia.

“We request a meeting with Russia and all participating states within 48 hours,” Kuleba said in a tweet. “If Russia is serious when it talks about the indivisibility of security in the OSCE space, it must fulfil its commitment to military transparency in order to de-escalate tensions and enhance security for all.”

Since early this year, Russia has amassed close to 1.3 lakh troops at the Ukrainian border. The two countries have been engaged in a conflict since 2014 when Russia annexed Ukraine’s Crimean Peninsula and backed separatist rebellions in the country’s eastern regions of Donetsk and Luhansk.

However, Russia has consistently denied the speculation that it would invade Ukraine.

Ukranian President Volodymyr Zelensky (Left) and US President Joe Biden. | AFP

On Sunday, Ukraine President Volodymyr Zelensky invited United States President Joe Biden to visit, saying that his presence could “contribute to de-escalation” in Kyiv, The New York Times reported.

During a phone call, the two leaders agreed on the importance of continuing to pursue diplomacy and deterrence in response to Russia’s military build-up on Ukraine’s borders, The White House said.

A serviceman stays in guard as he boat patrols water area of Ukraine's Black Sea port of Mariupol on February 11, 2022. | Aleksey Filippov / AFP

Meanwhile, National Security Adviser Jake Sullivan said that Russia could invade Ukraine “at any time” and might create a surprise pretext for an attack, according to Reuters.

“We cannot perfectly predict the day, but we have now been saying for some time that we are in the window,” Sullivan said.

On February 12, Biden had told Russian President Vladimir Putin that Washington and its allies would “respond decisively” if the Kremlin attacked Ukraine. Biden had also ordered most of its diplomats and other staff members to leave the American Embassy in Ukraine.