Secretary of State John Kerry will travel to Ukraine on Tuesday to meet with both legislators and civilians, the Obama administration announced Sunday afternoon as European leaders called for calm in the midst of international outrage over Russia’s hostile takeover of Crimea.
A senior administration official told NBC News that Kerry will travel to Kiev to meet with members of both the Rada (the Ukrainian parliament) and civil society.
Kerry on Sunday called Russia's incursion into Crimea — which is shaping into the worst East-West crisis since the Cold War — an “incredible act of aggression.”
President Barack Obama spoke separately with U.K. Prime Minister David Cameron, German Chancellor Angela Merkel and Polish President Bronisław Komorowski on Sunday, the White House said. They expressed “grave concern” over Russia's “clear violation of Ukrainian sovereignty and territorial integrit,” a statement said.
The leaders also said a dialogue between Ukraine and Russia should start immediately, according to the White House.
In another part of the U.S. diplomatic effort, Assistant Secretary of State Victoria Nuland will travel to Vienna on Sunday where she represent the United States at meeting of the Organization for Security and Cooperation in Europe, which will conduct a meeting on the Ukraine crisis.
Nuland recently made headlines when a conversation of her saying "F--- the EU" was leaked in reference to a diplomatic solution to the Ukraine crisis.
Meanwhile, a chorus of world leaders pleaded for cooler heads to prevail. While Pope Francis asked for prayers for Ukraine, German Foreign Minister Frank-Walter Steinmeier urged the international community to continue engagement with Russia and defended the country’s membership in the so-called G-8, the Group of Eight leading economies.
"It is still possible to turn around. A new division of Europe can still be prevented," Steinmeier said.
He told the public broadcaster ARD the G-8 was a "unique format" to continue speaking with Russia.
Kerry earlier Sunday had said events had "put at question Russia's capacity to be within the G-8." Russia has been a member since 1998.
Steinmeier also joined American voices in urging Russian President Vladimir Putin to order troops out of Crimea. Russian forces bloodlessly seized the Black Sea peninsula — where a majority of Russian speakers reside and Moscow has a major naval base — over the past few days.
"It is a very dangerous situation there," Steinmeier said.
NATO issued a statement saying it "condemns Russia's military escalation in Crimea" and demanding that Russia respect its obligations under the United Nations charter.
Ukraine is not a NATO member so the U.S. and Europe are not obligated to come to its defense. Ukraine has, however, requested admission to the group of Western allies and has taken part in some alliance exercises.
NATO's Anders Fogh Rasmussen warned that Russia's actions were unacceptable and could destabilize the continent. "What Russia is doing now in Ukraine violates the principles of the United Nations charter," Rasmussen told reporters.
He called on Russia to de-escalate tensions, withdraw from bases and "refrain from any interference elsewhere in Ukraine." He also urged Russian an Ukraine to begin speaking immediately seek a peaceful resolution through dialogue.
Another G-8 member, Italy, joined in calling Russia to exercise restraint, saying any invasion of Ukraine was “totally unacceptable.”
"The Italian government supports the pressing requests of the international community for Ukraine's sovereignty and territorial integrity to be respected," Prime Minister Matteo Renzi's office said in a statement.
"Any violation of these principles would be totally unacceptable for Italy," it added.
For his part, Putin told Merkel Sunday in a phone conversation that Russian citizens and Russian-speakers in Ukraine faced an "unflagging" threat from ultranationalists and that the measures Moscow has taken were justified because of the "extraordinary situation," the Kremlin said in a statement.
According to the Kremlin, Merkel and Putin agreed that Russia and Germany would continue talking in bilateral and multilateral formats to seek the "normalization" of the situation.
Merkel’s spokesman characterized the phone call differently, saying that the German chancellor had accused Putin of breaching international law with “unacceptable Russian intervention.”
Kristen Welker of NBC News, Reuters and The Associated Press contributed to this report.