West Ham have signed Czech Republic defender Vladimir Coufal for an undisclosed fee.
The 28-year-old right-back joins the Hammers from Slavia Prague on a contract until the summer of 2023, with the option of a further two years.
"I'm very happy I am part of the West Ham family," Coufal told the official club website. "I will do everything so that West Ham will be successful.
"I know about the interest West Ham had in me for a long time but now finally I am here and I am so happy.
"Tomas (Soucek) told me on the best things, that it's a good stadium with good fans and perfect teammates and staff.
"Tomas is my very good friend and I hope he will help me here."
Hammers manager David Moyes said of the eight-times capped Coufal: "He is a player we have been tracking for some time now and all of our reports have been very impressive.
"He has a lot of attributes and qualities that we believe will enable him to adapt quickly to the demands of the Premier League.
"Vladimir fits the profile of the type of player we want to bring to the football club – hungry, ambitious and determined.
"He is a proven talent with Champions League and international experience, but we believe his best years are still ahead of him here at West Ham.
"We need to give Vladimir some time to settle in and get used to his new surroundings but having Tomas Soucek here will help him in that sense, and we are confident that he will make a positive impact and prove to be a great addition to the squad."
Coufal played for Hlucin and Slovan Liberec before joining Slavia Prague in 2018, winning the Czech league title twice at the capital club.