Foreign ministers from France, Germany, and Poland are to hold crisis talks in Kyiv after deadly clashes this week.
The meetings with Ukrainian government officials and the opposition on February 20 come before an EU foreign ministers meeting in Brussels to decide whether to impose sanctions against Ukraine.
Meanwhile, a tense calm was reported overnight on the streets of Kyiv as thousands of protesters remain on Independence Square.
At least 28 people have been killed in clashes between police and antigovernment protesters this week -- the worst bloodshed since protests erupted against President Viktor Yanukovych last November. The Health Ministry said 287 people remained hospitalised, including 88 police officers and six journalists.
Late on February 19, Yanukovych and opposition leaders agreed to "a truce." In a statement, the president said "negotiations" would now start to stabilize the situation.
Opposition leader Arseniy Yatsenyuk -- who took part in the meeting -- said: "The storming of the Maidan (Independence Square) which the authorities had planned today will not take place."
U.S. President Barack Obama cautiously welcomed news of the truce while on a visit to Mexico.
"We've obviously seen reports about a truce between the government and opposition. If the truce is implemented it could provide space for the sides to resolve their disagreements peacefully," Obama said.
"And going forward, we will continue to do whatever we can to support Ukrainians as they seek a peaceful solution and respond to the aspirations of the Ukrainian people for a strong, unified democracy that is fully integrated into the international community."
Earlier, the State Department announced a U.S. visa ban on 20 senior Ukrainian officials and warned of more action in concert with the EU if the violence in Ukraine continues.
NATO leaders urged Ukraine's armed forces to stay out of the crisis there, warning Kyiv that its relations with the Western alliance would suffer if the military did intervene.
Also on February 19, President Yanukovych sacked the head of the Ukrainian armed forces, Volodymyr Zamana, and replaced him with Yuriy Ilyin, the naval chief.
The dismissal came after the Defense Ministry said the armed forces could participate in a nationwide "antiterrorist" operation being prepared by the Security Service.
The latest upsurge in violence erupted just days after tensions appeared to ease after the government implemented a conditional amnesty for people who were detained since the antigovernment demonstrations began three months ago.
The antigovernment movement was triggered by Yanukovych's decision not to sign cooperation accords with the European Union and instead accept a $15 billion bailout from Russia.
Based on reporting by AFP, AP, and Reuters