President Joe Biden is close to publicly naming his ambassador to Ukraine, but his administration is still waiting on formal approval from the Ukrainian government, US and Ukrainian sources told CNN.

Biden has selected Bridget Brink, the current US ambassador to Slovakia, but hasn't officially nominated her yet because the Ukrainian government hasn't signed off, according to a source familiar.

Getting approval from the foreign government is part of the standard process in selecting ambassadors and can usually take anywhere from days to weeks. A source close to Ukrainian President Volodymyr Zelensky told CNN on Monday that the Ukrainian government is still vetting Brink.

A senior official in Ukraine stressed there was no delay in the process, noting that the US proposed the new ambassador candidate about a week ago and the candidate was now undergoing a standard review.

Secretary of State Antony Blinken said recently the US ambassador to Ukraine would be announced "very shortly," adding, "I can tell you that when an ambassador is nominated, that person will have the full confidence of the President of the United States, that person will be someone that is well known to me and with whom I have a close relationship, and that person will have very demonstrable expertise and knowledge in this region."

Currently the chargé d'affaires, Kristina Kvien, remains at the embassy in Ukraine. The US has not had a permanent ambassador in the country since Marie Yovanovitch, who was pushed out of the position after she said she was effectively "kneecapped" by former President Donald Trump's administration.

The State Department last week ordered that families of diplomats at the US Embassy in Kyiv leave the country amid heightened tensions with Russia and allowed non-essential staff to depart voluntarily. The vast majority of staffers have chosen to stay, however, sources told CNN last week.

The US has become increasingly concerned that a Russian invasion of Ukraine could come at any time as Russia moves more troops and military equipment along Ukraine's border. White House press secretary Jen Psaki said last week that a Russian invasion is "imminent."

Biden said Monday the US and its partners and allies are preparing for "every scenario" after a key United Nations Security Council meeting on the situation on the Russia-Ukraine border.

The President said in a statement that the US "made clear to the international community the full implications of that threat — not just for Ukraine, but for core tenets of the UN Charter and the modern international order."

As part of its latest effort by the US to deter Russia from attacking Ukraine, the Biden administration identified several elite Russian government officials and business leaders the US intends to sanction if Russia invades Ukraine, CNN previously reported.

A senior official said "specific sanctions packages" have been developed against Russian elites "in or near the inner circles of the Kremlin and play a role in government decision-making, or are at a minimum complicit in the Kremlin's destabilizing behavior." Their families would be sanctioned too, the official said.

Biden said last week he would consider sanctioning Russian President Vladimir Putin himself if Russia invaded. But the official declined to reveal the names of the particular individuals the US is eying for potential sanctions, since the administration does not want the individuals to have any prior warning.

In addition, the two top senators on the Foreign Relations Committee -- Republican Sen. Bob Menendez of New Jersey and Democratic Sen. Jim Risch of Idaho -- said Sunday they are confident they will get a bipartisan deal on Russian sanctions when the Senate comes back from recess. The Senate returned from recess on Monday.

This story has been updated with additional information.
CNN's Matthew Chance contributed to this report.


Ambassador Bridget Brink’s Bio: Ambassador Brink arrived in the Slovak Republic on August 15, 2019.

A career member of the Senior Foreign Service, Ambassador Brink was sworn in as Ambassador to the Slovak Republic on July 1, 2019.  She most recently served as Deputy Assistant Secretary in the Bureau of European and Eurasian Affairs at the Department of State (2015-2018), with responsibility for issues related to Eastern Europe, the Caucasus, and the protracted conflicts in Europe.  She also served as Deputy Chief of Mission at the U.S. Embassies in Tashkent, Uzbekistan (2014-2015) and in Tbilisi, Georgia (2011-2014).

During her more than twenty years in the Foreign Service, Ambassador Brink has spent most of her career focused on advancing U.S. policy in Europe and Eurasia.  She was the Director for the Aegean and the South Caucasus at the National Security Council (2009-2010) and served in the State Department as the Deputy Director for Southern European Affairs (2008-2009), Special Assistant to the Under Secretary for Political Affairs (2002-2004) and Cyprus Desk Officer (1999-2002).  She began her career in Belgrade, Serbia (1997-1999).

Originally from Michigan, Ambassador Brink joined the State Department in 1996.  She holds Master’s degrees in International Relations and Political Theory from the London School of Economics and Political Science as well as a Bachelor’s degree in Political Science from Kenyon College.  Ambassador Brink speaks Russian and Serbian, as well as basic Georgian and French.

LINK to Ambassador Bridget Brink’s Bio: