Valjent was first called up to the
Slovakia national team by
Ján Kozák sr. for fixtures against
Netherlands and
Morocco on 31 May and 4 June 2018 respectively. This was done due to
Gyömbér and
Štetina's injuries. Valjent debuted during a match against Morocco in
Geneva, replacing
Tomáš Hubočan in the 79th minute. Valjent's first competitive start came in a
Euro 2020 qualifying fixture against
Croatia on 6 September 2019 in Trnava, with Valjent playing as a right-back. Slovakia lost the game 4–0. It was that Valjent had a difficult task in defending
Dejan Lovren at the side-line, as his preferred post is the one of a
centre-back. In October, Valjent returned to the national team in a friendly match against
Paraguay on his preferred post. His performance was reported on very positively, receiving praise from
RTVS' commentary expert
Marián Zeman during the farewell game for
Martin Škrtel, with whom he starred in the starting XI, as well as Hubočan and
Adam Nemec. This game also coincided with a return to
Tehelné pole after some ten years and ended in a 1–1 draw. On 26 August 2020, Valjent was called up by the Slovak senior squad to take part in the two opening matches of the
UEFA Nations League against the
Czech Republic and
Israel. Slovak media intensively speculated about the possible reasons for Valjent's continued exclusion from the national team after 2022, in spite of his consistent performances in La Liga. The manager of the national team
Francesco Calzona refused to elaborate on the absence of call-ups, although he praised Valjnet's professionalism and positive attitude in the national team. ==Career statistics==