US Secretary of State Antony Blinken departed Monday to Europe to rally support for Ukraine, on a trip where he could cross paths with his Russian counterpart.
Blinken, consumed for more than a month with the Israel-Hamas war and a US-China summit, was bound for talks with NATO foreign ministers in Brussels.
Blinken is then expected to head Wednesday to a meeting in North Macedonia of the Organization for Security and Co-operation in Europe (OSCE), said James O'Brien, the top US diplomat for Europe.
"We anticipate that he'll engage in a good discussion with our OSCE colleagues about support for Ukraine," O'Brien told reporters.
He said Blinken's schedule was subject to change and did not comment on whether he would consider seeing Russian Foreign Minister Sergei Lavrov, who has asked to be permitted to attend the annual meeting of the pan-European security body in which Russia is a member.
Lavrov said Monday that North Macedonia, which has joined Western sanctions over Russia's invasion of Ukraine, would allow him to take part, but he would still need permission to cross the airspace of EU member Bulgaria.
"Bulgaria has reportedly promised Macedonia to open its airspace. If it does, we will be there," Lavrov said, as quoted by the Russian state news agency TASS.
Last year, OSCE host Poland refused to let Lavrov attend, sparking an angry response from Russia.
US officials have refused most top-level contact with Russia since the invasion, although Blinken briefly met Lavrov in March on the sidelines of a Group of 20 meeting in India.
In Brussels, Blinken will speak about US support for Ukraine over the coming months, with Kyiv pursuing a counter-offensive at a time that much of global attention has shifted to the Middle East.
President Joe Biden's administration is trying to persuade the rival Republican Party to approve another $61 billion in aid to Ukraine, which he has tied to support for Israel and Taiwan.
O'Brien said the administration was confident about support in Congress for Ukraine and cast the aid as a "coalition effort," with Kyiv paying for 60 percent of its military costs and US allies supporting parts of the rest.
"I think it's important for our partners to hear that we'll continue to do our part, even while our Congress is debating the next steps of what we'll provide," O'Brien said.