The head of American diplomacy Antony Blinken left on Monday for Europe, where he should discuss with allies his country’s support for Ukraine and could also meet with his Russian counterpart, Sergei Lavrov, at a time when bilateral relations are cold.

Concerned for more than a month about the conflict between Israel and the Palestinian Islamist group Hamas, but also about the meeting between President Joe Biden and his Chinese counterpart Xi Ping, the US Secretary of State is expected to initially arrive in Brussels to participate of the meeting of heads of diplomacy of the NATO member states.

The US secretary of state is turning his attention to Ukraine, NATO and the Western Balkans after weeks of intense focus on the war between Israel and Hamas.

In Brussels, the alliance will reaffirm its support for Ukraine against the Russian invasion, explore ways to reduce tensions between Kosovo and Serbia and begin preparations for NATO’s 75th anniversary ceremonies next year.

The conclave between Tuesday and Wednesday will include the first meeting at the level of foreign ministers of the NATO-Ukraine Council, a body created by alliance leaders at their last summit to improve cooperation and coordination and help Kiev prepare for its eventual integration.

“Allies will continue to support Ukraine’s self-defense until Russia ends its war of aggression,” said Jim O’Brien, the top U.S. diplomat for Europe.

He will then attend a meeting in North Macedonia of the Organization for Security and Cooperation in Europe (OSCE) on Wednesday, according to O’Brien.

There has been violence between Serbia and Kosovo in recent months and Western countries fear that Russia is trying to foment instability in the Balkans to divert attention from the war in Ukraine.

“We hope that you will participate in a discussion with our OSCE colleagues on support for Ukraine” in the face of the invasion launched by Russia in February 2022, James O’Brien told reporters.

According to the diplomat, the Secretary of State’s agenda will probably change. He also declined to comment on the possibility of a meeting in North Macedonia with Russian Foreign Minister Sergei Lavrov.

Lavrov asked to participate in the annual meeting of the OSCE, an organization of which Russia is a member.

On Monday, the senior official announced that North Macedonia had authorized him to participate in the meeting, but that he would have to wait for Bulgaria to allow him to fly over its airspace.

“Bulgaria has promised (Northern) Macedonia to open its airspace. If it does, we will be there,” Lavrov declared, according to the official Russian agency TASS.

Last year, Poland hosted the OSCE meeting and rejected the presence of the head of Russian diplomacy, prompting strong protests from Moscow.