U.S. Vice President Joe Biden has pledged that the United States will "stand by the people of Kosovo" and urged the country to continue normalizing ties with neighboring Serbia and improve the rule of law.
Biden was speaking in the Kosovar capital, Pristina, on August 17 following meetings with President Hashim Thaci and Prime Minister Isa Mustafa.
Biden held similar talks in Serbia on August 16.
Serbia does not recognize Kosovo -- a former Serbian entity that declared independence in 2008 -- as an independent state.
Normalized bilateral relations are considered a precondition for Serbia and Kosovo to gain EU membership, which both countries seek.
But an EU-brokered deal between Belgrade and Pristina to improve and regulate relations between the two states has only been moderately successful.
In Pristina, Biden urged the two neighbors to make every effort to implement the normalization agreement.
"Both sides have responsibility to follow through on the commitments made in Brussels and to look for new areas to keep the dialogue moving forward once that's done -- it can't be the end, it should be the beginning," he said. "This is critical for advancing Kosovo and Serbia's full integration into Europe."
The U.S. vice president expressed hopes of welcoming "a democratic, multiethnic Kosovo" into the European family, urging the country's leaders to continue to improve.
"The rule of law has to apply equally to everyone," he said. "The justice system has to be equitable and it has to be transparent."
"The only way for Kosovo to move forward is to assure a united future and to advance reconciliation, to ensure that the rights of every citizen [are] protected," he added.
Biden highlighted the importance of fighting against graft and organized crime, describing corruption as a cancer that eats away at the fabric of every society in which it exists.
He said it was "absolutely critical that a government continue to fight impunity" by closing loopholes in the Criminal Code, professionalizing public appointments, and taking a zero-tolerance approach to corruption. The latter, he said, includes preventing indicted and convicted officials from continuing in their positions, and increasing the democratic accountability of the government.
Speaking before Biden, Thaci thanked the U.S. vice president -- a strong supporter of Kosovo during its struggle for independence -- for being "the voice" of Kosovo.
Thaci said Kosovo had strengthened peace and regional cooperation and made steps toward normalizing ties with Serbia.
He insisted that good-neighborly relations with Serbia were a "strategic goal" for his country, which he pledged would not remain "a prisoner of the past."
'Beau Biden Street'
Later on August 17, Biden attended a ceremony in the southeast of the Balkan country to unveil a street named after the vice president's son, Beau, who died of brain cancer in 2015.
Beau Biden, a former Delaware attorney general, served in 2001 as an interim legal adviser on postwar Kosovo, helping train local prosecutors and judges for the Organization for Security and Cooperation in Europe (OSCE). He also served one year in Iraq, from 2008 to 2009, with the U.S. National Guard.
WATCH: U.S. Vice President Joe Biden made an emotional visit to Pristina on August 17, recalling how his late son, Beau Biden, had made him realize how important it was for Kosovo to achieve independence -- and stating that the country's success was crucial for the wider region as a whole.
Biden flew to Kosovo late on August 16 from Serbia, where he held talks with Serbian President Tomislav Nikolic and Prime Minister Aleksandar Vucic.
In Belgrade, Biden encouraged Serbia to normalize its relations with Kosovo and offered condolences to the victims of the Kosovo conflict and NATO air attacks that helped end it in 1999.
"I'd like to add my condolences to the families of those whose lives were lost during the wars of the '90s, including as a result of the NATO air campaign in terms of responsibility," said Biden -- the first high-ranking U.S. official to express such sentiments in Serbia.
WATCH: U.S. Vice President Joe Biden has offered condolences to the families of Serbs who were killed in NATO air strikes during the Kosovo conflict in 1999.
For his part, Vucic pointed to a new future in Kosovar-Serbian relations.
"We think a different future is ahead of us, in which we will be able to seek agreement rather than aiming at each other with guns," he said.
Many in Serbia still resent the NATO air strikes and U.S. support for Kosovo's drive for independence. Belgrade also has close relations with Moscow and many politicians are very pro-Russia.
Biden is participating in one of his last major foreign tours as vice president.
On August 22-25, he will travel to Turkey, where he will meet with the three Baltic presidents, and Sweden for a meeting on energy security.