President Donald Trump said Thursday that a third country could join a groundbreaking peace agreement between the United Arab Emirates and Israel.

“Next week at the White House we’ll be having a signing between the UAE and Israel, and we could have another country added into that. And I will tell you that countries are lining up that want to go into it,” Trump told reporters at a press briefing.

Delegations from Israel and the UAE will attend a signing ceremony on Sept. 15. The UAE has agreed to normalize its relations with Israel, with the Israeli government agreeing to halt its plans to annex parts of the West Bank. 

“You’ll be hearing other countries coming in over a relatively short period of time. And you could have peace in the Middle East,” Trump continued. “I think what ultimately will happen is you’re going to have quite a few countries come in. The big ones are going to be coming in. I spoke to the king of Saudi Arabia, so we’re talking. We just started the dialogue. And you’ll have them come in.”

The Saudi Embassy in Washington has not commented on Trump’s statements. Saudi Arabia and Bahrain have agreed to allow Israeli flights to use their airspace following the announcement of the UAE-Israel accord in August.

Saudi Arabian King Salman bin Abdulaziz has previously said that his country would not pursue normalization with Israel, unless there was peace between the Israelis and Palestinians. Oman could be another country to normalize ties with Israel, but Oman’s leadership has suggested that normalization would not be possible unless a sovereign Palestinian state was established.

The Israel-UAE peace agreement was the first treaty between Israel and an Arab state in more than 25 years. In 1994, Israel signed a peace treaty with neighboring Jordan, and in 1979, the Jewish state signed an agreement with Egypt.

There are currently 30 United Nations member states that do not recognize Israel. Some countries, such as Lebanon, bar entry of foreign travelers who have Israeli stamps in their passports.