KYIV, Feb 14, 2022 (BSS/AFP) - German Chancellor Olaf Scholz lands in Kyiv

on Monday before visiting Moscow to try to head off a "very critical" threat
of a Russian invasion that could spark the worst crisis since the Cold War.

  The German leader visits the two capitals in reverse order from that taken
last week by French President Emmanuel Macron in his bid to quiet the
drumbeats of war echoing across eastern Europe.

  Russian President Vladimir Putin has surrounded Ukraine from nearly all
sides with more than 100,000 soldiers in a high-stakes standoff with the West
over NATO's post-Soviet expansion into countries once under the Kremlin's
domain.

  The West has remained united and defiant in the face of Putin's demands for
binding security guarantees that would see NATO roll back its forces and rule
out Ukraine's potential membership of the alliance.

  But US intelligence officials worry that weeks of crisis talks have given
Russia the time to prepare a major offensive -- should Putin make the
ultimate decision to attack Ukraine.

  Washington reaffirmed its warning Sunday that Russia was now ready to
strike at "any moment" with an assault that would likely start with "a
significant barrage of missiles and bomb attacks".

  US President Joe Biden briefed Ukrainian leader Volodymyr Zelensky on
Sunday about his hour-long phone call with Putin the previous day. Biden's
talks with Putin broke no new ground, the White House said.

  - Invitation to Biden -

  US officials said Biden and Zelensky had "agreed on the importance of
continuing to pursue diplomacy and deterrence" in their call.

  The Ukrainian presidency said Zelensky had also urged Biden to visit Kyiv
"in the coming days" in a show of moral support.

  The White House made no mention of the invitation in its readout of the 50-
minute call.

  But Germany's Scholtz sounded firm in his resolve to support Ukraine and
hit Russia "immediately" with punishing sanctions if it went to war.

  "In the event of a military aggression against Ukraine that threatens its
territorial integrity and sovereignty, that will lead to tough sanctions that
we have carefully prepared and which we can immediately put into force,"
Scholz said on the eve of his departure.

  "We assess the situation as very critical, very dangerous," a German
government source added.

  - Tough trip -

  Germany and France both play a central role in mediation efforts around the
gruelling conflict in Ukraine's Russian-backed separatist east that has
claimed more than 14,000 lives.

  But Germany's close business relations with Moscow and heavy reliance on
Russian natural gas imports have been a source of lingering concern for
Kyiv's pro-Western leaders as well as Biden's team.

  Scholz has warned Russia it should "not underestimate our unity and
determination" but also hedged against unequivocally backing Biden's pledge
to "bring an end" to Russia's new Nord Stream 2 gas link to Germany.

  Kyiv is also upset with Berlin for not having joined some of its NATO
allies in beginning to supply weapons to Ukraine.

  Scholz's visit to Moscow on Tuesday will be clouded by a spat involving the
tit-for-tat closures of the German-language channel of Russia's RT network
and the Moscow bureau of Germany's Deutsche Welle.

  British Prime Minister Boris Johnson will also "travel to Europe" to
address the crisis towards end of the week as part of the European push for
peace, his office said Sunday.

  - Air travel worries -

  The diplomatic push comes as Western countries withdraw staff from their
Kyiv embassies, with many of them urging their citizens to leave immediately.

  But departures may be complicated by the looming threat of the skies over
Ukraine closing due to rising risks for airlines.

  The Dutch carrier KLM became the first major airline over the weekend to
indefinitely suspend flights to Kyiv.

  Ukraine's budget airline SkyUp said its flight from Portugal to Kyiv was
forced to land in Moldova Sunday after the plane's Irish leasing company
revoked permission for it to cross into Ukraine.

  SkyUp added that European leasing companies were demanding that Ukrainian
airlines return their planes to EU airspace within 48 hours.

  Industry analysts believe other international airlines may soon also ban
flights into Ukraine because of the growing cost to insurers.

  The travel industry is still haunted by the memory of Malaysia Airlines
flight MH17, shot down while flying near eastern Ukraine's conflict zone in
July 2014.

  All 298 passengers and crew on board the Amsterdam-Kuala Lumpur flight were
killed.

  The diplomatic drawdown has also touched the staff of the Organization for
Security and Co-operation (OSCE) monitoring mission in Ukraine.

  The mission said "certain participating states" had asked their staff to
leave Ukraine "within the next days".

  But it stressed that its mission continued in 10 cities throughout the
country.