President Joe Biden announced on Wednesday, as he arrived at the NATO summit in Spain, that the U.S. would step up its military presence in eastern Europe amid Russia’s invasion of Ukraine.

Biden announced the U.S. would establish a permanent troop presence in Poland and maintain an additional rotational brigade of 3,000 fighters and 2,000 personnel in Romania. The troops in Poland will be the first permanent U.S. forces on NATO’s eastern flank. Biden said the U.S. would also enhance its rotational deployments in the Baltic region, which is comprised of Estonia, Latvia, and Lithuania. “We’re stepping up,” Biden said. Ukrainian President Volodymir Zelenskyy is expected to address the 30 NATO leaders via video link Wednesday, as Russia’s invasion stretches into its fifth month. The gathering has already seen a breakthrough agreement between Turkey and Finland and Sweden for the Nordic countries to begin their accession process. They asked to join the alliance after witnessing Russia’s brutal attack on its neighbor Ukraine, but Turkey had some misgivings that were overcome Tuesday.