The European Union has called for "calm, wisdom, restraint, and leadership" to prevail after the detention and expulsion of a senior Serbian government official by Kosovo authorities fueled friction between the two neighbors.
EU foreign-policy chief Federica Mogherini made an urgent trip to Belgrade on March 27 for talks with Serbian President Aleksandar Vucic, after ethnic Serbs walked out of Kosovo's government and set up a road block in the north of the country.
Following her meeting with Vucic, Mogherini said in a statement that she "deplored yesterday's events in Kosovo: What happened yesterday must not happen again."
The EU official and the Serbian president "agreed to find new ways to continue working and resolving peacefully issues between Belgrade and Pristina," the statement added.
The U.S. State Department in a statement late on March 27 said the United States "strongly condemns" the arrest and expulsion of a Serbian official from Mitrovica on March 26, events that it said "unnecessarily heighten tensions and threaten regional stability."
Department spokeswoman Heather Nauert urged the two Balkan nations to "avoid further escalation" over their differences and "focus on normalizing relations" through the EU-led dialogue.
Earlier in the day, politicians representing Kosovo's Serbian minority announced the decision to leave the Pristina government after they met with Vucic in Belgrade, saying they will no longer support Prime Minister Ramush Haradinaj's cabinet.
Haradinaj called their decision to pull out "incomprehensible" and insisted that his team "will not fall."
Serbs have also parked trucks to block a key road linking northern Kosovo with the capital.
The developments came a day after Marko Djuric was briefly detained after entering the ethnically divided town of Mitrovica because authorities said he had entered the country illegally.
Djuric, who is the head of the Serbian government’s office for Kosovo, was transferred to a court in Pristina before being expelled from the country.
Officers also fired tear gas to disperse a crowd of ethnic Serbs protesting against the arrest.
Russia's Foreign Ministry said Moscow "strongly" condemned the incident in Mitrovica, alleging that it was "aimed at intimidating Kosovo Serbs."
Serbia's former province of Kosovo declared independence in 2008 and is recognized as a sovereign state by well over 100 countries but not by Belgrade and Moscow.
EU-brokered negotiations between the leaders of Kosovo and Serbia in Brussels on March 23 broke up without apparent progress toward an agreement to normalize relations, which the bloc wants completed by the end of 2019.