The phrase "agreed to observe the" is correct and usable in written English.
It can be used in contexts where individuals or parties are committing to follow certain rules, guidelines, or agreements.
Example: "The parties involved have agreed to observe the terms outlined in the contract."
Alternatives: "committed to following the" or "consented to adhere to the".
Pomahac agreed to observe the procedure, to see how he could be unobtrusive.
Later that year the Chinese signed the Beijing Convention, in which they agreed to observe the treaties of Tianjin and also ceded to the British the southern portion of the Kowloon Peninsula adjacent to Hong Kong.
If all countries agreed to observe the minimum levels of domestic public health financing proposed by the SDSN, many would have to adapt taxation levels accordingly, and that could mitigate the downward pressure on taxation and social policy levels caused by the quest for competitiveness in a globalized market – or so we will examine.
Mayor Dickinson said that he admired Dr. King and his achievements, but that he would not agree to observe the holiday unless the labor unions that represent town workers first agreed to give up one of their other paid holidays.
In Thursday morning's session the two teams agreed to observe a minute's silence to remember the victims of "terrorism" – but quickly blamed each other for perpetrating the violence.
On that occasion, the British media had been aware of the deployment but agreed to observe a strict media blackout.
The Palestinians have suspended their intifada: most of the armed factions have agreed to observe a truce, though they call it merely a tahdia, or "lull".
The mortar fire interrupted a ceasefire called for by the UN on humanitarian grounds, which both Israel and Hamas had agreed to observe between 0700 GMT and 1200 GMT.
A federation is a group of nations who have agreed to observe rules of peaceful conduct in their mutual relations (1795, 98ff).
It may still be useful for groups of governments (like the Council of Europe) to band together to agree to observe certain standards.
What's more, they got Google, Microsoft, Yahoo and AOL to agree to observe them.
