Ukrainians arrive in California from the Mexican city of Tijuana, where a massive operation is helping thousands of Ukrainian refugees cross the border to resettle in the United States. "It was very very hard eight days, because we sleep in airport with children," says Alina Pakhomova after arriving in the United States. Hundreds of Ukrainians have reached the border town of Tijuana in hopes of crossing onto US soil -- encouraged by a promise from Washington that it is prepared to welcome up to 100,000 Ukrainians who have fled the war. Pavel Savastyanov, a Russian-born volunteer helping at a support center for Ukrainians in San Ysidro, California -- just across the border from Tijuana -- says every flight to the area is bringing more. IMAGES AND SOUNDBITES