WASHINGTON -- US President Donald Trump on Monday signed a proclamation recognizing Israel's sovereignty over the disputed Golan Heights, territory that Israel seized from Syria in 1967.

The proclamation said that it is "appropriate to recognize Israeli sovereignty over the Golan Heights" because of the security need of Israel.

"This was a long time in the making," Trump said before signing the decree at the White House with visiting Israeli Prime Minister Benjamin Netanyahu standing alongside.

Netanyahu welcomed Trump's move and called the recognition "historic."

Israel seized the Golan Heights from Syria in a war in 1967 and annexed it in the 1980s, but the international community has never recognized the move.

Recognizing the Israeli sovereignty over the Golan Heights has been a recent demand by Israeli Prime Minister Benjamin Netanyahu, which comes months after the Trump administration moved the US embassy in Israel from Tel Aviv to Jerusalem.

The Syrian Foreign Ministry on Monday condemned Trump's recognition of the Syrian Golan Heights as Israeli territory, the state news agency SANA reported.

The ministry said in a statement that Trump's move is a "flagrant violation of the sovereignty of Syria," adding that the Syrian government completely rejects the decision and the Golan Heights will always remain a Syrian territory.

"Trump does not have the legal right to legitimize the occupation of others' land by force," the ministry said.

The UN Security Council in a December 1981 resolution called Israel's annexation of the Golan Heights "null and void and without international legal effect" — and the UN says Secretary-General Antonio Guterres adheres to council resolutions.

UN spokesman Stephane Dujarric said Monday that Guterres' position remains unchanged despite President Donald Trump's formal recognition of Israel's sovereignty over the Golan Heights.

Guterres said in a report on recent activities of the UN peacekeeping force on the Golan Heights that he was "gravely concerned" at escalating tension there between Israel and Syria. He circulated the report on Monday to the Security Council.

The secretary-general singled out three incidents between Syria and Israel between Nov 20 and Feb 11.