Secretary of State Antony Blinken is traveling to Ukraine, Germany, and Switzerland this week - a sign "perhaps that diplomacy is not dead," a senior State Department official said Tuesday.

       As Russia continues to mass troops and military equipment near Ukraine's borders, including now in allied Belarus, the U.S. and European countries have become increasingly concerned the Kremlin may be preparing to launch an attack on Ukraine.

       But Blinken will meet his Russian counterpart, Foreign Minister Sergei Lavrov, in Geneva on Friday, keeping the door to diplomacy open.

       "This is an extremely dangerous situation. We're now at a stage where Russia could at any point launch an attack in Ukraine," White House press secretary Jen Psaki said Tuesday -- a sharp rise in the United States' rhetorical warnings that Russian lead Vladimir Putin may attack his neighbor.

       Before sitting down with Lavrov, Blinken will meet Ukrainian President Volodymyr Zelenskiy and Foreign Minister Dmytro Kuleba in his second visit to Kyiv as secretary, along with his German, French, and British counterparts for a summit in Berlin.

       Russian Foreign Ministry/Anadolu Agency via Getty Images

       Secretary of State Antony Blinken and Russian Foreign Minister Sergey Lavrov meet on the sidelines of the Organization for Security and Co-operation in Europe (OSCE) meeting in Stockholm, Sweden, Dec. 2, 2021.

       Months of Russian troop buildups and bellicose rhetoric led to a series of high-stakes diplomatic meetings last week. But the one-on-one U.S.-Russia talks, a summit between NATO and Moscow, and a meeting of the Organization for Security and Cooperation in Europe ended inconclusively.

       Putin laid out his demands in two draft treaties last month, including that Ukraine be barred from joining NATO and that the Western military alliance pull its troops out of Eastern European member states. But for weeks, the U.S. and NATO have called those nonstarters, instead offering to negotiate on other issues like arms control or military exercises and threatening massive sanctions if Russia attacks Ukraine.

       Russia has denied that it plans to invade Ukraine, where its troops have led eastern forces in a war against the government for eight years now and continue to occupy the peninsula Crimea. It has warned that if its demands aren't met, it will respond with "military technical" measures.

       Defense Ministry of Belarus/AFP via Getty Images

       This handout photograph released on Jan. 18, 2022 by Belarus' Defense Ministry, shows a Russian troop train transporting military vehicles arriving for drills in Belarus.

       Rather than tensions defusing, the threat of conflict seems to be rising, engineered by Russian moves. The Kremlin has begun moving troops into Belarus, Ukraine's neighbor to the north, for military exercises next month, including troops from its far east, Russia's Defense Ministry confirmed Tuesday, saying the exercises were designed to prepare Russian and Belarusian forces to "thwart and repel a foreign aggression."

       "This is neither an exercise nor normal troop movement," the senior State Department official told reporters. "It is a show of strength designed to cause or give false pretext for a crisis as Russia plans for a possible invasion."

       "This movement of forces into Belarus clearly gives the Russians another approach, should they decide to take further military action against Ukraine," they added, saying the U.S. had been in "nonstop" contact with Ukraine and NATO allies since the movements began over the weekend.

       Last Friday, the White House said the U.S. had intelligence that Russia had positioned operatives trained in urban warfare and explosives for a possible "false-flag" operation that could also been used as pretext for an invasion - something the Kremlin denied as "complete disinformation."

       Blinken and Lavrov spoke Tuesday and agreed to meet Friday in Geneva, where U.S. and Russian delegations met last week. Their meeting will be another attempt to deescalate tensions, but it's unclear what new ground there is to tread.

       "It is still too early to tell if the Russian government is genuinely interested in diplomacy, if it is prepared to negotiate seriously in good faith, or whether it will use discussions as a pretext to claim that diplomacy didn’t address Moscow’s interest. I just can’t judge that now, but I do understand the desire on our side to test that hypothesis," the senior State Department official said.

       Before traveling to Switzerland, Blinken will be hosted by Zelenskiy in Kyiv, days after a bipartisan delegation of U.S. lawmakers visited and vowed continued U.S. support too, including arms.

       "As we speak there are additional U.S. supplies that are being sent to Ukraine to make sure that they have what they need to fight back," Sen. Chris Murphy, D-Conn., told ABC News.

       In between Kyiv and Geneva, Blinken will meet German Foreign Minister Annalena Baerbock for the second time this month, with the new German government critical to the strength of any potential sanctions if Russia invades. Blinken and Baerbock will also meet their French and British counterparts in a show of diplomatic solidarity.