From ICAN

The Netherlands is a signatory of the nuclear Non-Proliferation Treaty (NPT) and has signed and ratified the Comprehensive Test Ban Treaty (CTBT), being one of the 44 listed countries needed to sign and ratify for the CTBT to enter into force. Earlier suspicions have been confirmed.

The Netherlands, Belgium, Germany and Turkey have US nuclear weapons situated on their soil, the Wikileaks whistleblower files have revealed.

The four countries, along with Italy, had long been suspected of being home to a collection of American nuclear armaments, but neither the states nor Nato had ever officially confirmed or denied their presence…
The memo also confirms the presence of US nuclear weapons in Turkey.

Italy is also believed to be a silent custodian of American weapons of mass destruction.

Asked by EUobserver whether the country will now reassess its ambivalent public position on the matter in the wake of the leaks, the Dutch foreign ministry continued to stick by its long-standing stance, saying that there would likely be no comment forthcoming on the issue of US nuclear weapons.

From the Wikileaks site

TACTICAL NUCLEAR WEAPONS

¶8. (C) In response to Gordon’s question about how the
government planned to take forward the commitment in the
coalition agreement to seek the removal of all remaining
nuclear weapons from Germany, Heusgen distanced the
Chancellery from the proposal, claiming that this had been
forced upon them by FM Westerwelle. Heusgen said that from
his perspective, it made no sense to unilaterally withdraw
“the 20” tactical nuclear weapons still in Germany while
Russia maintains “thousands” of them. It would only be worth
it if both sides drew down. Gordon noted that it was
important to think through all the potential consequences of
the German proposal before going forward. For example, a
withdrawal of nuclear weapons from Germany and perhaps from
Belgium and the Netherlands could make it very difficult
politically for Turkey to maintain its own stockpile, even
though it was still convinced of the need to do so.